In the past decade nanoscience, nanotechnology, and associated applications have witnessed significant upgradation from the perspective of fundamental, applied, and translational research. The art of nanoengineering has opened up prevailing prospects for a variety of applications, where numerous innovations and discoveries have followed the scientific research in this domain. To present a broad understanding of the subject matter, in this chapter, we provide a comprehensive introduction to the book by elaborating on the synthesis, classification, characterization, functionality, and applications of nanoengineered materials. Efforts are made to present integrated scientific approaches that would benefit chemists, physicists, and biologists working with basic as well as advanced functional materials with unique optoelectronic assets and biophysicochemical interfaces. We believe that such an exhaustive capture of the fundamentals of nanoengineering would lay a strong foundation for students, researchers, academicians as well as industry-based scientists.

Inducing post-transition metals in an oxide semiconductor system has a high potential for use in storage for neuromorphic computing. It is challenging to find a material that can be switched stably between multiple resistance states. This research explores the memristive properties of Sn (post-transition metal)-doped ZnO (SZO) thin films, emphasizing their application in memristor devices. The (magnetron sputtered) synthesized SZO thin films in the form of Ag/SZO/Au/Ti/SiO? device demonstrated a clear bipolar resistive switching (BRS) behavior with VSET and VRESET of 1.0 V and ?0.75 V, respectively. The memristor could change between a high resistance state and a low resistance state with a high RON/OFF rate of 104, mimicking synaptic behaviors such as potentiation and depression. This switching is attributed to the formation and dissolution of Ag filaments within the SZO layer, influenced by the migration of Ag? ions and the presence of oxygen vacancies. These vacancies facilitate the formation of conductive filaments under positive bias and their dissolution under negative bias. The endurance and retention tests showed stable switching characteristics, with the memristor maintaining distinct HRS and LRS over 100 cycles and retaining these states for over 5K seconds without significant degradation. Finally, the nonlinearity values for potentiation and depression were ?p?1.6 and ?d ? -0.14, suggesting that the memristor may be more responsive to increasing synaptic weights in biological systems. The linearity response at a very small pulse width showed the device is more applicable for neuromorphic applications. The observed memristor combined with stable endurance and retention performance, suggests that this memristor structure could play a crucial role in the development of artificial synapses and memory technologies. © 2024 Elsevier Ltd

Plastic-aggregates are made up from unused or waste plastic and natural aggregates which have recently been emerged as a significant addition to the existing emerging contaminants list mainly in the coastal environment. The transformation from plastics/microplastics to Plastic-aggregates signifies a crucial shift in our understanding and use of plastics and prompting us to reconsider their fundamental characteristics along with possible environmental threats. When plastic waste is incinerated for the purpose of disposal, it combines with organic and inorganic substances present in the surrounding environment, leading to a new type of material. Besides, some natural factors (physical, chemical, biological or in combination) also act upon discarded plastics to combine with rocks and other earthen materials to form plastic-aggregates. Our research aims to build fundamental knowledge and critically review the possible formation process, classification, and possible degradation of all such polymer-rock compounds along with their impact on the ecosystem. The knowledge gap related to the degradation and release of secondary pollutants from these agglomerates is to be addressed urgently in future research. Development and standardization of proper sampling and reporting procedures for plastic-aggregates can enhance our understanding related to their impacts on human health as well as to the entire environment as these aggregates contain different toxic chemicals

The development of direct methanol fuel cells (DMFCs) relies on designing replacements for benchmark platinum (Pt)?based electrocatalysts toward methanol oxidation reaction (MOR) that exhibit high resistance to CO poisoning, improve kinetic sluggishness, devoid of unwanted intermediates, low catalyst cost, and wide operating conditions. This study presents the development of defect engineering N?doped graphene oxide (NG) supported ZnWO4 nanocuboids as an efficient catalyst for photoelectrochemical MOR and electrochemical ORR. Under visible light (420 nm), the NG/ZnWO4 nanohybrid exhibits exceptional photoelectrochemical MOR with low potential of 0.5V with a high oxidation peak current density of ?10 mA cm?2 is recorded while comparing with benchmark catalyst Pt/C. In two electrode systems for DMFC, the catalyst reaches an impressive maximum power production of 111 mW cm?2 with very stable charge?discharge cycles of 0.33 mV cycle?1, which is far superior to ZnWO4’s alone. Simultaneously, the nanocomposite exhibits excellent ORR activity in alkaline medium with improved onset half?wave potential of 0.85V, high current density of 5.8 mA cm?2 at 1600 rpm, and robust stability, attributed to the synergistic effect between NG and ZnWO4. This work has reinforced these findings with theoretical insights using the Vienna Ab initio Simulation Package (VASP) to assess both PMOR and ORR performance and reaction intermediates.

The authors regret the oversight in one of the author's (Manjunatha Thondamal) affiliation details occurred during the final proof reading. The affiliation detail for the author- Manjunatha Thondamal is: d Department of Biotechnology, School of Technology, Gandhi Institute of Technology and Management (GITAM), Visakhapatnam, Andhra Pradesh, 530045, India. The authors would like to apologise for any inconvenience caused.

Carbon dots (CDs), versatile carbon?based luminescent nanomaterials, offer environmental friendliness, cost?effectiveness, and tunable optical properties for diverse optoelectronic applications, including LEDs, photodetectors, and flexible electronics. These nanoscale materials exhibit unique optical behaviors like highly tunable photoluminescence (PL) and efficient multiphoton up?conversion. This study explores how precursor selection influences CDs' sp²/sp³ hybridization ratios and their optoelectronic properties. CDs were synthesized from four distinct sources: polymeric Polyvinylpyrrolidone (PVP), protein, biomass, and citric acid. Biomass? and protein?derived CDs displayed remarkable photocurrent enhancements under blue light, attributed to balanced sp²/sp³ ratios, while polymer?derived CDs showed limited optoelectronic response. These findings reveal the critical role of precursor composition in tailoring the structural and electronic properties of CDs, offering sustainable pathways for their application in advanced optoelectronic devices.

Highly crystalline hematite (?-Fe2O3) nanostructures (NSs) with distinct morphology hold vital significance, not only for fundamental knowledge of magnetic properties but also offering potential applications from biomedical to data storage to semiconductor industry, etc. ?-Fe2O3 NSs with various shapes are examined to reveal the intrinsic relationship between the shape anisotropy and magnetic properties. Herein, different morphologies of ?-Fe2O3 NSs, such as spherical, cubic, plate-like, rhombohedral, and hexagonal bipyramid are synthesized, by controlled hydrothermal method. The impact of shape and size on the optical and structural characteristics through UV–vis absorption spectroscopy and X-ray diffraction is analyzed. Advanced nanomaterial techniques such as transmission electron microscopy are utilized to explore and confirm the morphology and size of NSs. Subsequently magnetic properties of the ?-Fe2O3 NSs, such as magnetic saturation (Ms), coercivity (Hc), and remanent magnetization (Mr), are measured. Careful analysis of magnetic data reveals Morin transition around 200K for cubic, plate-like, and rhombohedral samples, whereas the spherical and hexagonal bipyramid samples illustrate the superparamagnetic behavior in the temperature range of 150–300K. Finally, the antibacterial characteristics of NSs against Escherichia coli using a microplate reader for monitoring the bacterial growth are investigated

Reduced graphene oxide (rGO) has captivated the scientific community due to its exceptional electrical conductivity, high specific surface area, and excellent mechanical strength. The physical properties of reduced graphene oxide (rGO) are strongly dependent on the presence of different functional groups in its structural framework, along with surface roughness. In this study, laser annealing was employed by a nanosecond Nd:YAG laser to investigate the impact of varying laser energies on the wettability and conductivity of reduced graphene oxide (rGO) samples grown by the pulsed laser deposition (PLD) technique. The rGO films were annealed with different laser fluences, such as 10, 20, 30, 38, 48, 55, and 250 mJ/cm2. Our results reveal a notable transition in wettability, transforming the initially hydrophobic rGO samples into a hydrophilic state. Hydrophilic graphene oxide (GO) or reduced graphene oxide (rGO) surfaces have significant potential for use in biomedical applications due to their unique combination of properties, including biocompatibility, high surface area, and abundant oxygen-containing functional groups. Along with wettability properties, conductivity changes were also observed. The presented findings not only contribute to the understanding of laser-induced modifications in rGO but also highlight the potential applications of controlled laser annealing in tailoring the surface properties of graphene-based materials for diverse technological advancements

Developing an efficient and durable electrocatalysts for oxygen electrolysis is crucial for advancing clean energy technologies. However, the sluggish kinetics of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), along with catalyst degradation, remain major obstacles. Here, we optimized the composition of composite nanocatalysts obtained by doping of an electron deficient, B-atoms into graphene quantum dots (GQD) attached with Cobalt Sulfide (CoS) nanostructures. Optimizing the surface structure and investigating the interfacial interactions, the catalyst demonstrated an exceptional oxygen electrode reaction performance. The faster electronic synergism between the defect engineering BGQD and CoS offers more catalytic active sites as well as faster electrical conductivity and higher adsorption/desorption rate of oxygenated intermediates at the electrode surface for the electrolysis processes. Among the optimized composite electrode material CSBGQD-13 (CoS/BGQD (1:3)) exhibited high positive onset (Eonset = 1.04 V vs. RHE) and half-wave potential (E1/2 = 0.84 V vs. RHE) with high limiting current density of 7.6 mA/cm2 at 1600 rpm and a reasonable resistance to the MeOH crossover effect during ORR. In addition, our electrocatalyst demonstrated long-term durability and effective OER activity with the lowest Tafel slope of 82 mV/dec among other CSBGQDs and a lower overpotential of 0.27 V vs. RHE at a current density of 10 mA/cm2. Furthermore, the CSBGQD-13 claims excellent dual function electrocatalytic performance towards ORR and OER with a very small ?E value (only 0.66 V vs. RHE), a higher catalytic current density. Henceforth, for possible fuel cell applications, we believe that this electrode material may provide an understanding of the principles of metal sulfide carbon dots hybrid catalysts

The hybridization of biomolecules with gold nanoclusters (AuNCs) has emerged as a promising research direction in bioelectronics, extending multidimensional prospects for diverse applications, from wearable health monitoring to advanced medical devices and tissue engineering. Here, we report a hybrid of bovine serum albumin (BSA) protein and gold nanoclusters of various concentrations to harness the distinctive properties of gold nanoclusters and enhance the electronic functionalities of biomolecules. Self-assembled monolayers (SAMs) of hybrid materials demonstrate enhanced electrical conduction with a film thickness of 10–15 nm as obtained from atomic force microscopy topographical images, revealing minimal aggregation. Current–voltage (I–V) characteristics at ±0.5 V showed significantly higher current densities for optimized hybrid material (BSA-Au6) SAMs, reaching 150 A/cm2. Compared to prior studies on BSA and metal hybrid thin films, the observed 100-fold enhancement in electrical conductivity for AuNC-doped SAMs highlights the novelty of this work. Moreover, our study with different AuNC concentrations demonstrated that six equivalents of AuNCs significantly boosted conductivity due to efficient electron transport mechanisms, which was further investigated with electrical impedance measurements. Our findings provide valuable insights into the underlying electronic transport mechanisms across hybrid materials for applications in bioelectronics and molecular electronics, marking a breakthrough compared to conventional protein films.

Renewable energy has gained widespread recognition for its potential to drive sustainable power generation and mitigate climate change. However, the rapid expansion of these resources highlights inherent challenges arising from their non?dispatchable, intermittent, and asynchronous nature, underscoring the critical need for grid?scale energy storage. Although numerous storage technologies exist, cohesive insights into commercially available or nearing commercialization remain limited. The review addresses that gap by presenting a comprehensive analysis of marketable grid?scale energy?storage solutions. The discussion begins with an examination of growth dynamics and regional trends in energy?storage capacities worldwide. By using California and Saudi Arabia as representative samples of the Mediterranean and hot desert regions under the Köppen classification, the review illustrates how climatic zones influence energy?storage requirements. After highlighting recyclability challenges associated with lithium?ion batteries, the study explores emerging electrochemical and gravitational?storage technologies. It then articulates critical parameters for evaluating energy?storage solutions and provides a comparative performance analysis. The review concludes by identifying a range of commercialized innovations and recommending a holistic approach to strengthen reliance on renewable energy

Tiny sized (?2 nm) copper nanoclusters (Cu NCs) were synthesized with strong optical response, where red/green emitting features were observed using protein/amino acid as surfactant molecules. The photocatalytic water splitting reactions for both ligand-mediated Cu NCs were carried out in a photochemical reactor under solar simulator for 12 h. Interestingly, protein mediated red colour emitting Cu NCs produced stable H2 ? 256 mmol g?1 and the solar to hydrogen efficiency (STH) is approximately ? 0.5% while comparing with green emitting Cu NCs with 86 mmol g?1 and STH of 0.08%. These interesting results were achieved due to their longer lifetime, strong colloidal stability, high quantum yield and rich surface functionalization features. These were further confirmed through absorption spectroscopy, fluorescence spectroscopy, time-resolved photoluminescence, zeta potential, high resolution transmission electron microscopy and X-ray photoelectron spectroscopy analytical techniques. Thus, these inexpensive Cu NCs could be used as alternate photocatalysts for H2 production than obviating the usage of precious noble metal platinum-based ones

Gold nanoclusters (Au NCs) have found wide range of applications in environmental, chemical and health sectors as sensors, catalytic agents and theranostic molecules, respectively, due to their ultrasmall size and excellent optical properties. However, a comprehensive battery of bioassays of Au NCs were lacking on a well-established biological model system, which would enhance its potential to be used as an optical probe with application in theranostics. The current investigation aims to address the in vivo compatibility of Au NCs to improve their design, evaluate their biological impact, and validate their potential for bioimaging applications. We have used the Caenorhabditis elegans as a model organism in our present study due to their short life cycle facilitating evaluation of drug effects in reasonable time frame and transparent body framework suitable for in vivo imaging. These features facilitate accurate information regarding the uptake and biodistribution of Au NCs inside the tissues and body parts. Additionally, different nanotoxicological studies such as biodistribution of NCs and its subsequent impact on the health span, brood size, pharyngeal pumping and tail thrashing of C. elegans were observed as a measure of the Au NCs biocompatibility. Our results strongly demonstrate that the human serum albumin (HSA)-bound Au NCs are non-toxic, biocompatible and do not exhibit any adverse effect on the physiology and survival of the C. elegans. This study, employing a comprehensive battery of bioassays, is the first to systematically evaluate the long-term biocompatibility and non-toxicity of Au NCs across the entire lifespan of an organism, measured through multiple physiological parameters. These findings underscore the potential of Au NCs as safe and effective diagnostic and therapeutic agents for medical and clinical applications

This article reports facile fabrication of a multifunctional smart surface having superhydrophobic self-cleaning property, superoleophilicity, and antimicrobial property. These smart surfaces have been synthesized using the stereolithography (SLA) method of the additive manufacturing technique. SLA is a fast additive manufacturing technique used to create complex parts with intricate geometries. A wide variety of materials and high-resolution techniques can be utilized to create functional parts such as superhydrophobic surfaces. Various materials have been studied to improve the functionality of 3D printing. However, the fabrication of such materials is not easy, as it is quite expensive. In this work, we used a commercially available SLA printer and its photopolymer resin to create various micropatterned surfaces. Additionally, we applied a low surface energy coating with ZnO nanoparticles and tetraethyl orthosilicate to create hierarchical roughness. The wettability studies of created superhydrophobic surfaces were evaluated by means of static contact angle using the sessile drop method and rolling angle measurements. The effects of various factors, including different concentrations of coating mixture, drying temperatures, patterns (pyramids, pillars, and eggbeater structures), and pillar spacing, were studied in relation to contact angles. Subsequently, all the functional properties (i.e., self-cleaning, oleophilicity, and antibacterial properties) of the as-obtained surfaces were demonstrated using data, images, and supporting videos. This inexpensive and scalable process can be easily replicated with an SLA 3D printer and photopolymer resin for many applications such as self-cleaning, oil–water separation, channel-less microfluidics, antibacterial coating, etc

Improving and reducing the cost of electrochemical performance is critical to developing energy storage technology. In this study, we investigated the effects of incorporating NiSe2 into the MoSe2, then the electrochemical behaviour of MoSe2@NiSe2 (0D/1D) hybrid-nanostructure prepared using a hydrothermal method. The Scanning electron microscopy (SEM) images confirmed that MoSe2, MoSe2@NiSe2 (0D/1D) hybrid-nanostructure in composites with surface enhancement. The MoSe2@NiSe2 (0D/1D) hybrid-nanostructure exhibits enhanced specific capacitance of 802 F g?1 compared to MoSe2 and shows extended cycle life up to 5000 cycles with 92.7 % of capacity retention. In addition, the active electrode consisting of MoSe2@NiSe2 (0D/1D) hybrid-nanostructure exhibits high ionic affinity due to the presence of abundant electrochemically active sites, which can reduce the internal resistance and lead to accelerated ion transport. Our results demonstrate that a simple and scalable approach can significantly improve the electrochemical performance of the MoSe2@NiSe2 (0D/1D) hybrid nanostructure

Novel dielectrics with electrostatic energy storage capabilities attracted significant attention in recent years for high-energy storage applications due to their high-power density. The structural, electrical, and dielectric properties play a pivotal role in attaining high power densities in dielectric ceramics. Here, the authors presented the influence of CaTiO3 on the structural, electrical, and dielectric properties of BiFeO3-CaTiO3 (BFO-CTO) lead-free ceramics. (BFO)(1?x)–(CTO)x (x=0, 0.1, 0.3, and 0.5 and 1) ceramics were fabricated from calcined powders of BFO and CTO using the microwave sintering technique. Due to the partial substitution of Ca2+ and Ti4+ into the A and B sites (of Bi3+ and Fe3+, respectively) structural phase transformation occurred from rhombohedral to orthorhombic crystal structure for x?0.3. As the CTO concentration is increased, the resistivity of BFO-CTO samples is enhanced by two orders of magnitude, from 2.21×103 ? cm (x=0) to 8.80×105 ? cm (x=0.5). The leakage current density was reduced by two orders of magnitude, from~2.60×10–1 A cm?2 (x=0) to~2.50×10–3 A cm?2 (x=0.5). The improved resistivity, reduced leakage current and enhanced dielectric properties make lead-free BFO-CTO dielectrics as an excellent alternative to existing energy storage systems.

An efficient method for the synthesis of isoindolinones and isoquinolinones from 1,2,3-benzotriazin-4(3H)-ones under visible light is described. The reaction of 1,2,3-benzotriazin-4(3H)-ones with activated alkenes such as acrylonitrile, vinyl ketone, acrylates and vinyl sulfones in the presence of DIPEA under blue LED light irradiation gave isoindolinones in good to high yields. In a similar manner, the reaction of aromatic terminal alkynes with 1,2,3-benzotriazin-4(3H)-ones gave 3-substituted isoquinolinones. This method avoids the use of any metal or external photocatalysts and is believed to proceed via electron donor-acceptor (EDA) complex formation facilitated by DIPEA and 1,2,3-benzotriazin-4(3H)-ones. The practical applicability of these reactions is also demonstrated by performing gram-scale synthesis of isoquinolinones and isoindolinones. Moreover, the utility of this method was showcased through the synthesis of an anxiolytic drug pazinaclone analogue in high yield. © 2024 The Royal Society of Chemistry.

Self-cleaning surfaces revolutionizing the technology world due to their novel property of cleaning themselves, and its multi-functional self-cleaning surfaces exhibit at least one or more functional properties (transparent, conducting, anti-bacterial, anti-corrosion, etc.) This review article focuses on the fundamentals of wettability, material parameters controlling surface wettability and three different paths to realization of self-cleaning surfaces, i.e., (i) super-hydrophobic, (ii) super-hydrophilic and (iii) photocatalytic. The subsequent part of the article mostly focuses on the super-hydrophobic path towards realizing self-cleaning surfaces. In the super-hydrophobic path, the objective is to make the surface extremely repellent to water so that water droplets slide and ‘roll off’ from the surface. The next section of the review article focuses on the role of additive manufacturing in the fabrication of super-hydrophobic micro-structures. Amidst the different fabrication processes of self-cleaning surfaces, additive manufacturing stays ahead as it has the manufacturing capacity to create complex micro-structures in a scalable and cost-effective manner. A few prominent types of additive manufacturing processes were strategically chosen which are based on powder bed fusion, vat photopolymerization, material extrusion and material jetting techniques. All these additive manufacturing techniques have been extensively reviewed, and the relative advantages and challenges faced by each during the scalable and affordable fabrication of super-hydrophobic self-cleaning surfaces have been discussed. The article concludes with the latest developments in this field of research and future potential. These surfaces are key to answer sustainable development goals in manufacturing industries. Graphical abstract: (Figure presented.) © The Author(s) 2024.

Hydrogen is emerging as a strong contender for a feasible future energy carrier in the clean energy race, due to its high energy density and clean burning nature. However, to account for the environmental and energy challenges, its production must be sustainable and cost-efficient. Currently, hydrogen is generated from various feedstocks such as ammonia, methane, natural gas, biomass, smaller organic molecules, and water. These feedstocks undergo different catalytic processes, including catalytic decomposition, electrolysis, steam reforming, pyrolysis, gasification, and photoassisted methods such as photoelectrochemical, biophotolysis, and photocatalysis, etc. Among all, the research on water electrolysis has garnered much attention because of their carbon free green hydrogen production with the use of water electrolyzers (WEs). On the basis of recent reports from the International Renewable Energy Agency (IREA), the major types of water electrolyzers used in the industry are alkaline water electrolyzers (AWE), proton-exchange membrane water electrolyzers (PEMWEs), and anion-exchange membrane water electrolyzer (AEMWE). Among them, AWEs and PEMWEs have their inherent drawbacks which need attention. AEMWEs can be considered as a promising alternative by integrating the advantages of both AWEs and PEMWEs into one device. In this review, we have focused on the core ideas of AEMWEs, where the recent scientific and engineering breakthroughs are highlighted. It points out the importance of eliminating the gap between electrodes (i.e., zero gap concept) and identifies areas that need further development to push AEMWE technology forward. AEMWEs offer advantages such as higher operating current densities and pressures, comparable Faradaic efficiencies (>90%), and the utilization of nonprecious metal catalysts along with pure water feed. Along with all these, we have also focused on the advancements and deterioration of AEMs. Additionally, it provides a concise overview of AEMWE membrane performance and offers a detailed examination of developments in electrolyte feeding and the utilization of nonprecious group metal (non-PGM) electrocatalysts. © 2024 American Chemical Society.

The ceria-tin/alumina mixed metal oxides (Ce/Sn =1) with different proportions of Fe & Mn dopants were synthesized and investigated in detailed approach for diesel emission reduction. The dopants created structural defects enhancing the oxygen ion mobility for exhaust treatment. The existence of surface-active oxygen sites and oxygen ion vacancy sites generated for charge compensation due to reduction of Ce4+, Sn4+ and dopants incorporation evidenced from XPS analysis. The Mn doped sample holds better physicochemical properties than Fe doped sample. The Mn doped sample with higher surface area of about 101.32 m2 g?1 exhibits greater active sites for better catalytic activity. The redox couples in the Mn-doped sample Ce4+/Ce3+, Sn4+/Sn2+, and Mn3+/Mn2+ helps in oxygen regeneration to contribute to exhaust treatment by oxygen ion conduction from bulk to the surface. This sample exhibited the 92 % of NOx reduction and proved to be a dynamic candidate for diesel emission reduction. © 2024 Elsevier Ltd

The careful arrangement of nanomaterials (NMs) holds promise for revolutionizing various fields, from electronics and biosensing to medicine and optics. This review delves into the intricacies of nano-assembly (NA) techniques, focusing on oriented-assembly methodologies and stimuli-dependent approaches. The introduction provides a comprehensive overview of the significance and potential applications of NA, setting the stage for review. The oriented-assembly section elucidates methodologies for the precise alignment and organization of NMs, crucial for achieving desired functionalities. The subsequent section delves into stimuli-dependent techniques, categorizing them into chemical and physical stimuli-based approaches. Chemical stimuli-based self-assembly methods, including solvent, acid–base, biomolecule, metal ion, and gas-induced assembly, are discussed in detail by presenting examples. Additionally, physical stimuli such as light, magnetic fields, electric fields, and temperature are examined for their role in driving self-assembly processes. Looking ahead, the review outlines futuristic scopes and perspectives in NA, highlighting emerging trends and potential breakthroughs. Finally, concluding remarks summarize key findings and underscore the significance of NA in shaping future technologies. This comprehensive review serves as a valuable resource for researchers and practitioners, offering insights into the diverse methodologies and potential applications of NA in interdisciplinary research fields.

The increasing global demand for energy solutions has created the necessity for innovative nanocomposite materials for efficient energy storage applications. This urgency is driving significant advancements in energy storage technologies, raising hope for the future of energy sectors. Supercapacitors (SCs), high-performance electrochemical storage devices, have earned considerable attention to address these challenges. In this article, we have demonstrated a cost-effective, easily obtainable trimetallic spinel/defect-spinel oxide ZnMnO/CuMnO (ZMO/CMO) nanocomposite through a facile one-step solvothermal synthesis process. This nanocomposite demonstrated exceptional charge storage capabilities. The charge storage mechanism was established by using Dunn’s method, which reveals the diffusive nature of the electrode material. The ZMO/CMO nanocomposite exhibits an impressive specific capacitance of 468.1 F/g at 0.5 A/g, with 84% capacity retention even after 20000 cycles, which was attributed to the oxygen vacancies within the defect spinel structure. Moreover, we fabricated an asymmetric device utilizing ZMO/CMO as the cathode and activated carbon (AC) as the anode. This device attained an energy density of 48.1Wh/kg and a power density of 700 W/kg with excellent cycling stability, as mentioned before. Furthermore, our study featured its ability to power a standard LED light.

Recent research has concentrated on developing efficient and cost-effective co-catalysts to enhance photocatalytic applications, which are prominent among the various emerging techniques for harnessing easily accessible energy sources. The present work focuses on the hydrothermal approach to fabricate and thoroughly characterize tungsten selenium (WSe 2 ) nanoparticles using polyethylene glycol (PEG-4000) as their surfactant. The samples underwent advanced characterizations such as SEM and HRTEM to examine morphology, X-ray diffraction (XRD) to validate phase and crystal structure, photoluminescence (PL) and Raman studies for defect density determination, Fourier transform infrared (FTIR) spectroscopy for analyzing functional groups and bonds, and XPS for insights into elemental composition and chemical state of the hybrid nanostructures. A comparative analysis was conducted, utilizing both bare WSe 2 and WSe 2 /PEG nanostructures, to observe their enhanced photocatalytic degradation efficiency and degradation kinetics on RhB. The superior photocatalytic performances were attributed to enhanced pore size and reduced defect density in the WSe 2 /PEG nanostructures.

Reactive oxygen species (ROS) contain at least one oxygen atom and one or more unpaired electrons and include singlet oxygen, superoxide anion radical, hydroxyl radical, hydroperoxyl radical, and free nitrogen radicals. Intracellular ROS can be formed as a consequence of several factors, including ultra-violet (UV) radiation, electron leakage during aerobic respiration, inflammatory responses mediated by macrophages, and other external stimuli or stress. The enhanced production of ROS is termed oxidative stress and this leads to cellular damage, such as protein carbonylation, lipid peroxidation, deoxyribonucleic acid (DNA) damage, and base modifications. This damage may manifest in various pathological states, including ageing, cancer, neurological diseases, and metabolic disorders like diabetes. On the other hand, the optimum levels of ROS have been implicated in the regulation of many important physiological processes. For example, the ROS generated in the mitochondria (mitochondrial ROS or mt-ROS), as a byproduct of the electron transport chain (ETC), participate in a plethora of physiological functions, which include ageing, cell growth, cell proliferation, and immune response and regulation. In this current review, we will focus on the mechanisms by which mt-ROS regulate different pathways of host immune responses in the context of infection by bacteria, protozoan parasites, viruses, and fungi. We will also discuss how these pathogens, in turn, modulate mt-ROS to evade host immunity. We will conclude by briefly giving an overview of the potential therapeutic approaches involving mt-ROS in infectious diseases.

Semiconductor quantum dots (QDs) have been used in a variety of applications ranging from optoelectronics to biodiagnostic fields, primarily due to their size dependent fluorescent nature. CdSe nanocrystals (NCs) are generally synthesized via a hot injection method in an organic solvent. However, such NCs are insoluble in water and therefore preclude the direct usage toward biological systems. Thus, the preparation of more biocompatible water-soluble QDs with a high photoluminescent quantum yield (PLQY) is extremely important for imaging applications. Although previous literature has detailed on the synthesis of CdSe NCs in water, they suffer from poor size distribution and very low PLQY. The complex formation mechanism of CdSe NCs in an aqueous environment adversely affects the quality of NCs due to the presence of OH, H+, and HO moieties. Here in this article, we have presented the facile hydrothermal approach to obtain size tunable (2.9-5.1 nm), aqueous CdSe NCs with a narrow emission profile having ?40 nm fwhm with 56% PLQY. Physicochemical properties of the synthesized water-soluble CdSe NCs were studied with the help of UV-vis, PL, XRD, FTIR, XPS, and HR-TEM analysis. Furthermore, the surface of the synthesized CdSe NCs was modified with d-glucosamine via EDC and NHS coupling to obtain a stable, biocompatible bioimaging probe. Furthermore, we demonstrated that their successful bioconjugation with glucosamine could facilitate effective internalization into the cellular matrix.

One of the major constituents of mitochondrial membranes is the phospholipids, which play a key role in maintaining the structure and the functions of the mitochondria. However, mitochondria do not synthesize most of the phospholipids in situ, necessitating the presence of phospholipid import pathways. Even for the phospholipids, which are synthesized within the inner mitochondrial membrane (IMM), the phospholipid precursors must be imported from outside the mitochondria. Therefore, the mitochondria heavily rely on the phospholipid transport pathways for its proper functioning. Since, mitochondria are not part of a vesicular trafficking network, the molecular mechanisms of how mitochondria receive its phospholipids remain a relevant question. One of the major ways that hydrophobic phospholipids can cross the aqueous barrier of inter or intraorganellar spaces is by apposing membranes, thereby decreasing the distance of transport, or by being sequestered by lipid transport proteins (LTPs). Therefore, with the discovery of LTPs and membrane contact sites (MCSs), we are beginning to understand the molecular mechanisms of phospholipid transport pathways in the mitochondria. In this review, we will present a brief overview of the recent findings on the molecular architecture and the importance of the MCSs, both the intraorganellar and interorganellar contact sites, in facilitating the mitochondrial phospholipid transport. In addition, we will also discuss the role of LTPs for trafficking phospholipids through the intermembrane space (IMS) of the mitochondria. Mechanistic insights into different phospholipid transport pathways of mitochondria could be exploited to vary the composition of membrane phospholipids and gain a better understanding of their precise role in membrane homeostasis and mitochondrial bioenergetics.

High-quality copper oxide (CuO) thin films were deposited on the silicon (Si) substrate at the room temperature using the physical vapour deposition (PVD) technique named radio frequency (RF) sputtering. The copper-oxide thin-films were single crystalline and of uniform thickness. Subsequently, the influence of growth pressure (low gas pressure - 3 mTorr and high gas pressure - 100 mTorr) and post growth annealing at different temperatures (300 °C to 700 °C) were investigated to understand the microstructural and morphological changes of the thin film. With the influence of growth pressure and post thermal annealing temperature, significant changes in crystallinity, surface roughness, and surface oxidation rate of the CuO thin film were detected, which were adequately analyzed via several characterization techniques. X-ray diffraction (XRD) patterns revealed the phase formation with good crystallinity of the film, which is substantiated by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) characterization. Atomic force microscopy (AFM) images disclosed that the surface roughness of the film and grain size. By gaining insights into the structural and surface properties of CuO/Si thin films, this research presents new prospects for tuning of CuO phases, structures, and compositions for multifunctional applications.

Photovoltaic systems (PV), particularly solar photovoltaics, are gaining popularity as renewable energy sources. The rapid deployment of PV systems has attracted substantial investments, with around $170 billion projected by 2025. However, challenges like dust accumulation, solar radiation, and temperature rise hinder PV efficiency. Elevated temperatures, exceeding standard levels, notably decrease voltage output and overall electricity generation efficiency. This review provides a comprehensive overview of recent cooling techniques adopted to enhance solar PV performance. Beginning with an introduction to global warming's impact and renewable energy's significance, the article explores cooling methodologies for solar PVs. These encompass Absorption & adsorption-based, PV/T hybrid, Microtechnology-based, and Water and air-based cooling systems. The review concludes this section with a detailed table comparing cooling technologies' performance, benefits, and challenges. The review then delves into four primary cooling techniques: Active cooling, Passive cooling, Nanofluid-based cooling, and Thermoelectric cooling. Passive cooling, which effectively reduces PV system temperature without external energy sources, is highlighted. Modalities of Passive cooling methods, such as Radiative cooling, Evaporative cooling, Liquid immersions, and Material coatings, are elaborated. Concluding, the article addresses challenges, opportunities, and future prospects related to diverse cooling techniques' utilisation, aiming to elevate solar PV system efficiency.

Today, the world is struggling with the colossal amount of microplastics (MPs) due to the tremendous increase in the global production. Presence of MPs in the water samples, biological samples, and its potential to carry lethal chemicals raised the interest on better management of MPs. However, an effective degradation methodology is necessary to decrease the prolonged lifetime of such polymeric materials. So far, very limited reports are available on the degradation methods such as photo-oxidation, biodegradation, photo-thermal oxidative process, subsequent mechanisms involved during the degradation of MPs. Many critical challenges pertaining to those are poorly understood. Particularly, the extraction process, reliable methods to degrade MPs and their analytical techniques, level of MPs contamination in commercially caught fishes and the population at large. Here, we have revisited shortly on current MPs extraction process, various degradation methods using catalyst with their respective mechanisms. Also, the role of most common analytical methods/tools, to identify, analyse the degraded product from MPs, both environment samples and experimental samples, were elaborated. Finally, the solutions to overcome the problems were identified. Graphical Abstract: (Figure presented.)

This paper presents a comprehensive overview of the potential applications for Photo-Acoustic (PA) imaging employing functional nanoparticles. The exploration begins with an introduction to nanotechnology and nanomaterials, highlighting the advancements in these fields and their crucial role in shaping the future. A detailed discussion of the various types of nanomaterials and their functional properties sets the stage for a thorough examination of the fundamentals of the PA effect. This includes a thorough chronological review of advancements, experimental methodologies, and the intricacies of the source and detection of PA signals. The utilization of amplitude and frequency modulation, design of PA cells, pressure sensor-based signal detection, and quantification methods are explored in-depth, along with additional mechanisms induced by PA signals. The paper then delves into the versatile applications of photoacoustic imaging facilitated by functional nanomaterials. It investigates the influence of nanomaterial shape, size variation, and the role of composition, alloys, and hybrid materials in harnessing the potential of PA imaging. The paper culminates with an insightful discussion on the future scope of this field, focusing specifically on the potential applications of photoacoustic (PA) effect in the domain of biomedical imaging and nanomedicine. Finally, by providing the comprehensive overview, the current work provides a valuable resource underscoring the transformative potential of PA imaging technique in biomedical research and clinical practice.

The production of hydrogen (H) through photoelectrochemical water splitting (PEC-WS) using renewable energy sources, particularly solar light, has been considered a promising solution for global energy and environmental challenges. In the field of hydrogen-scarce regions, metal oxide semiconductors have been extensively researched as photocathodes. For UV-visible light-driven PEC-WS, cupric oxide (CuO) has emerged as a suitable photocathode. However, the stability of the photocathode (CuO) against photo-corrosion is crucial in developing CuO-based PEC cells. This study reports a stable and effective CuO and graphene-incorporated (Gra-COOH) CuO nanocomposite photocathode through a sol-gel solution-based technique via spin coating. Incorporating graphene into the CuO nanocomposite photocathode resulted in higher stability and an increase in photocurrent compared to bare CuO photocathode electrodes. Compared to cuprous oxide (CuO), the CuO photocathode was more identical and thermally stable during PEC-WS due to its high oxidation number. Additionally, the CuO:Gra-COOH nanocomposite photocathode exhibited a H evolution of approximately 9.3 µmol, indicating its potential as a stable and effective photocathode for PEC-WS. The enhanced electrical properties of the CuO:Gra-COOH nanocomposite exemplify its potential for use as a charge-transport layer.

The electrode material properties, such as widening the voltage window, rational design, and morphology are known to play an essential role in increasing its efficiency for energy storage devices. Herein, a simple strategy to first prepare a Mg(OH)/Cu(OH)(NO) (MHCN) binary heterostructure by co-precipitation method. The morphology studies from SEM and HR-TEM analysis revealed that the Mg(OH) and Mg(OH)/Cu(OH)(NO) binary heterostructures show quasi-spherical and nanosheet-like structures. The electrochemical characteristics of as-prepared binary heterostructure electrodes were investigated by a three-electrode system. At a low current density of 5 Ag, the specific capacitance of the MHCN-2 achieved 146 Fg. The MHCN-2 electrode displayed capacitance retention of ~ 97% and coulombic efficiency of ~ 96% for 5000 cycles. This study offers a facile and low cost approach for producing novel nanostructures and electrodes for energy storage in binary heterostructure materials. Graphical Abstract: [Figure : see fulltext.].

The Southeast Asian (SEA) region has witnessed a relentless surge in energy demand, driven by rapid urbanization, industrialization, and economic growth. In response, the exploration and development of renewable energy sources have gained significant attention. Among these sources, solar energy has emerged as a highly promising candidate due to its remarkable growth rate. This comprehensive review article aims to analyze the challenges and opportunities involved in maximizing solar energy production in the SEA region. The article commences with a succinct introduction to electromagnetic wave spectra and emphasizes the significance of visible spectra. It then provides a comprehensive examination of gross horizontal irradiance (GHI) patterns across the SEA region. A systematic tabulation is presented, organizing the current and potential solar energy installations and outputs of ASEAN countries. The article explores the deployment of hybrid photovoltaic (PV) systems, particularly floating PV installations, as an effective strategy to reduce dependence on fossil fuels. Moreover, the utilization of Supervisory Control and Data Acquisition (SCADA) systems for optimizing solar PV output is investigated. The article further delves into critical maintenance protocols, encompassing corrective, emergency, preventive, and predictive measures, and explores the levelized cost of electricity (LCOE) to assess the profitability of solar PV installations. Lastly, the leadership of Malaysia, Indonesia, and Singapore in solar PV research is highlighted, with a specific focus on building integrated PV and floating PV research. By addressing these, this review article offers valuable insights into the challenges and opportunities for advancing solar energy production in the SEA region.

This review article focuses on the role of nanotechnology (NT) in the development of advanced organic and inorganic photodetectors and their potential applications in the coming decades. We initiate the article with an overview of NT and potential applications of Nanotechnology in the twenty-first century ranging from Semiconductor manufacturing to Medical Imaging to Renewable energy to Quantum computing to Opto-electronics. The second part of the article delved into specific details on the role of nanotechnology and nanomaterials in developing advanced Photodetectors (PDs) and specifically discussing the internal functioning of near-infrared (NIR) photodetectors. Subsequently we focused on the performance metrics of PDs and types of PDs namely Organic Photodetectors (OPD) and Inorganic Photodetectors (IPD). We continued our in-depth discussion on OPDs and IPDs elaborating their structural features, operation mechanisms, types, performance optimization and role of functional nanomaterials. The final part of this review focuses on key applications of photodetectors e.g., retinal implant, biomedical imaging, personalized health monitoring, telecommunication, and military applications etc. Finally, we concluded the review paper discussing future opportunities and challenges regarding applications of NIR photodetectors in the twenty-first century. Graphical Abstract: [Figure : see fulltext.]

The existence of toxic, non-biodegradable organic pollutants in wastewater has become an indisputable global observation of environmental problems. Degradation of organic pollutants using advanced oxidative processes like Fe-Fenton oxidation gained significant attention due to its potential in elimination of dye molecules. However, its narrow pH operating window (2.5–3.5 pH) and the residual iron limits their wide application. In this study, the bovine serum albumin encapsulated - copper sulfide (BSA-CuS) NPs for efficient degradation of organic pollutants was proposed. BSA-CuS NPs were successfully synthesized using simple thermal decomposition process and their physicochemical properties were thoroughly characterized using UV-Vis spectroscopy, XRD, HRTEM, FTIR and XPS. The synthesized CuS NPs shows superior performance in degrading of model organic dye in wide pH range when compared to the conventional Fe-Fenton systems. Later the influence of H 2 O 2 sequential addition investigation revealed the enhanced degradation efficiency and its role was investigated with DFT hypothesis. The major contribution of active species responsible for the dye degradation was explored through scavenger study and reported the possible mechanism. Further the optimized condition was extended to real-time samples. Evaluation of recyclability, reduction in dissolved total organic carbon and antibacterial study evidence the potential of BSA-CuS as efficient and eco-friendly catalyst.

Surface functionalization has a prominent influence on tuning/manipulating the physicochemical properties of nanometer scaled materials. Ultrasmall sized nanoclusters with very few atoms have received enormous attention due to their bright fluorescence, biocompatibility, lower toxicity, good colloidal stability and strong photostability. These properties make them suitable for diagnostic applications. In this work, we intend to study the effect of surface functional ligands on their biodistribution both in vitro and in vivo organelle systems for bioimaging applications.

We have developed silver-nanostructures grown on anodic alumina nanomesh (AAN) films to create new-type substrates for surface-enhanced Raman scattering (SERS). AAN with uniform thin sidewall of ? 5 nm was fabricated by anodizing Al sheets at 1 V in 6% H 3 PO 4 solution. Subsequent AC electrochemical deposition of silver created an array of nanoparticles or nano-islands depending on growth time. The particle-island transition is non-monotonic evolution, since metal growth and dissolution compete in AC electrodeposition process. Systematic SERS study on various Ag-AAN films with trial probes of adenine solutions reveals collective contribution of electron-plasma oscillation and surface area of silver nanostructures in Raman enhancements. SERS signals are primarily contributed by surface area under excitation wavelength of 532 nm (away from plasmonic resonance). The average correlation coefficient between the SERS intensity and surface area was 0.85, indicating robust correlation. This value was reduced to 0.61 under excitation wavelength of 633 nm (closer to plasmonic resonance). Furthermore, increased Ag-deposition reduced the relative standard deviation of SERS intensities and thus improved both the uniformity and quality consistency of SERS substrates. Therefore, fabrication of SERS substrate with larger Ag surface area under similar SERS enhancement factors is suggested for high throughput in commercial sectors.

Functional metal nanomaterials, especially in the nanocluster (NC) size regime, with strong fluorescence, aqueous colloidal stability, and low toxicity, necessitate their application potential in biology and environmental science. Here, we successfully report a simple cost-effective method for red-/green-color-emitting protein/amino-acid-mediated Cu NCs in an aqueous medium. As-synthesized Cu NCs were characterized through UV-Vis absorption spectroscopy, fluorescence spectroscopy, time-resolved photoluminescence, dynamic light scattering, zeta potential, transmission electron microscopy and X-ray photoelectron spectroscopy. The optical properties of both Cu NCs responded linearly to the variation in pH in the neutral and alkaline ranges, and a robust pH reversible nature (between pH 7 and 11) was observed that could be extended to rapid, localized pH sensor development. However, a contrasting pH response nature between protein–Cu NCs and amino acid–Cu NCs was recorded. The alteration in protein secondary structure and strong binding nature of the surfactants were suggested to explain this behavior. Furthermore, we investigated their use as an efficient optical probe for fluoride ion detection. The limit of detection for protein–Cu NCs is 6.74 µM, whereas the limit of detection for amino acid–Cu NCs is 4.67 µM. Thus, it is anticipated that ultrasmall Cu NCs will exhibit promise in biological and environmental sensing applications.

Sputter grown copper (Cu) and titanium dioxide (TiO 2 ) based transparent solar heat rejecting film has been developed on glass substrates at room temperature for energy saving smart window applications. The performance of as-deposited ultra-thin TiO 2 /Cu/TiO 2 multilayers was elucidated, wherein the visible transmittance of the multilayer significantly depends on the crystal quality of TiO 2 layers. In-situ nanocrystal engineering of TiO 2 films with optimized sputtering power improves crystallinity of nano-TiO 2 domains. The transparent heat regulation (THR) coating with an average transmittance of ?70% over the visible spectral regime and infra-red reflectance of ?60% at 1200 nm was developed at room temperature. Optical characterization, X-ray diffraction (XRD), high resolution-transmission electron microscopy (HR-TEM) and atomic force microscopy (AFM) have been utilized to analyze the crystallinity of TiO 2 and quality of the multilayered structure. TiO 2 /Cu/TiO 2 based prototype device has been demonstrated for the energy saving smart windows application.

The structure formation of carbon nanodots (C-dots) prepared from three different organic precursors is discussed at the molecular level. During microwave synthesis, organic chromophores associated with C-dot structures are formed that exhibit distinct optical features. The molecular structure of these fluorophores is elucidated and their optical properties with and without the C-dots are investigated. The emergence of two-photon emission is observed and correlated with the hybridization state of the carbon atoms within the C-dot as well as the formation of the fluorophores. Varying contents of sp- and sp-hybridization in different C-dots also affect their one-photon and two-photon emission characteristics. Understanding the molecular structure of the carbon nanocore and the organic fluorophores formed in C-dots would enable rational design of C-dots with improved optical features, which would be of great relevance for their applications, for example, in bioimaging.

The interest in application of nanodiamonds as nanotheranostics is increasing rapidly over recent years. The combination of properties, such as high refractive index, low toxicity, inertness, high carrier capacity and rich surface functionalities, as well as unique magneto-optical properties of the nitrogen-vacancy centre, renders fluorescent nanodiamonds superior to other nanomaterials as nanotheranostics. In this review, the current state of research on the applications of nanodiamonds as theranostics where they have been utilised in combination with both diagnostics/imaging and therapy simultaneously is discussed. Firstly, a brief introduction to the current knowledge about the synthesis and properties of nitrogen-vacancy centre in nanodiamonds is given. Then, the underlying principles that are responsible for the magneto-optical properties of nitrogen-vacancy centre are explained. The majority of theranostic applications of nanodiamonds rely on the judicious engineering of their surface with bioactive molecules. In the following section, methods of engineering the surface of nanodiamonds while preserving their colloidal stability and their implication on in vitro and in vivo biocompatibility are described. Subsequently, the recent developments and applications of nanodiamond conjugates as photo-theranostics and non-targeted and targeted theranostics are critically discussed. Co-delivery of specifically tailored nanodiamonds with both diagnostic/imaging and therapeutic features can considerably contribute towards nanotheranostics-based personalized medicine. Graphical Abstract: [Figure : see fulltext.]

Energy is an essentials input for a holistic socio-economic development in industrial applications, where effective infrastructure plays a pivotal role. Historically, studies on a renewable energy source (RES) have been increased both in absolute and relative terms. RES can be envisioned as important dimension by addressing the issues of fossil fuel depletion and a global warming. Alternatively, Hydrogen (H 2 ) emerged as a renewable-energy-based product via integration of PV/PEC water splitting because it requires only 1.23 eV of thermodynamically potential to split the water. However, low efficiency of solar-to-hydrogen system (STH) as well as expensive photovoltaic (PV) cell is the main bottleneck for widespread commercial development of solar-based H 2 production. The price of electrical energy should be four times lower than the price of commercial electricity because STH system is so reliant on rising electricity bills. Several engineered devices has been invented and had studied to get high stability along with low lost. The highest efficiency of PV-PEC device was recently achieved by fabrication of integrated system with a Ni electrode and a multi-junction GaInP/GaAs/Ge solar cell, which delivers a solar water splitting efficiency about 22.4%. Also, metal chalcogenide (sulfide/selenide) is one of the best options with a good stability, low cost, high efficiency of H 2 and main application is solar energy harvesting and conversion. Synthesis of metal chalcogenide plays a major role in tunability of device infrastructure and results in increasing the efficiency. In this chapter we mainly focused on H 2 such as infrastructure, synthesis, stability, STH efficiency of the devices along with their pros and cons.

Near-infrared (NIR) light-activated photosensitization represents an encouraging therapeutic method in photodynamic therapy, especially for deep tissue penetration. In this context, two-photon activation, i.e., utilization of photons with relatively low energy but high photon flux for populating a virtual intermediate state leading to an excited state, is attractive. This concept would be highly advantageous in photodynamic therapy due to its minimal side effects. Herein, we propose that the combination of plasma protein serum albumin (HSA) containing several Ru complexes and NIR two-photon excitable carbon nanodots (Cdots), termed HSA-Ru-Cdots, provides several attractive features for enhancing singlet oxygen formation within the mitochondria of cancer cells stimulated by two-photon excitation in the NIR region. HSA-Ru-Cdot features biocompatibility, water solubility, and photostability as well as uptake into cancer cells with an endosomal release, which is an essential feature for subcellular targeting of mitochondria. The NIR two-photon excitation induced visible emission of the Cdots allows fluorescence resonance energy transfer (FRET) to excite the metal-to-ligand charge transfer of the Ru moiety, and fluorescence-lifetime imaging microscopy (FLIM) has been applied to demonstrate FRET within the cells. The NIR two-photon excitation is indirectly transferred to the Ru complexes, which leads to the production of singlet oxygen within the mitochondria of cancer cells. Consequently, we observe the destruction of filamentous mitochondrial structures into spheroid aggregates within various cancer cell lines. Cell death is induced by the long-wavelength NIR light irradiation at 810 nm with a low power density (7 mW/cm2), which could be attractive for phototherapy applications where deeper tissue penetration is crucial.

Proteins, a highly complex substance, have been an essential element in living organisms, and various applications are envisioned due to their biocompatible nature. Apart from proteins' biological functions, contemporary research mainly focuses on their evolving potential associated with nanoscale electronics. Here, we report one chemical doping process in model protein molecules (BSA) to modulate their electrical conductivity by incorporating metal (gold) nanoclusters on the surface or within them. The as-synthesized Au NCs incorporated inside the BSA (Au 1 to Au 6) were optically well characterized with UV-vis, time-resolved photoluminescence (TRPL), X-ray photon spectroscopy, and high-resolution transmission electron microscopy techniques. The PL quantum yield for Au 1 is 6.8%, whereas that for Au 6 is 0.03%. In addition, the electrical measurements showed ?10-fold enhancement of conductivity in Au 6 (8.78 × 10S/cm), where maximum loading of Au NCs was predicted inside the protein matrix. We observed a dynamic behavior in the electrical conduction of such protein-nanocluster films, which could have real-time applications in preparing biocompatible electronic devices.

Metal nanoclusters (NCs) composed of the least number of atoms (a few to tens) have become very attractive for their emerging properties owing to their ultrasmall size. Preparing copper nanoclusters (Cu NCs) in an aqueous medium with high emission properties, strong colloidal stability, and low toxicity has been a long-standing challenge. Although Cu NCs are earth-abundant and inexpensive, they have been comparatively less explored due to their various limitations, such as ease of surface oxidation, poor colloidal stability, and high toxicity. To overcome these constraints, we established a facile synthetic route by optimizing the reaction parameters, especially altering the effective concentration of the reducing agent, to influence their optical characteristics. The improvement of the photoluminescence intensity and superior colloidal stability was modeled from a theoretical standpoint. Moreover, the as-synthesized Cu NCs showed a significant reduction of toxicity in both in vitro and in vivo models. The possibility of using such Cu NCs as a diagnostic probe toward C. elegans was explored. Also, the extension of our approach toward improving the photoluminescence intensity of the Cu NCs on other ligand systems was demonstrated.

The Sun is an inexhaustible source of renewable energy, although under-utilized due to its intermittent nature. Hydrogen fuel is another clean, storable, and renewable energy as it can be readily produced by electrolysis of water, a naturally abundant resource. However, the necessary voltage for water electrolysis (>1.23 V) is high for the process to be cost effective, and therefore requires photoelectrocatalytic (PEC) cells for lowering the voltage. Powering the PEC cells with solar driven photovoltaic (PV) devices offers an all-clean efficient technology purely relying on renewable sources and therefore warrants large research attention. This review aims to provide an up to date account of the PV-PEC integrated technology for green hydrogen. We begin with the fundamentals of PV and water splitting technologies (electrolysis, photocatalysis, electrocatalysis (EC), photoelectrocatalysis (PEC)), as well as why and how the unassisted solar water splitting technology gradually progressed from PV with external electrolysers (PV-EC) to integration of PV with EC (IPV-EC) and PEC (PV-PEC). We then discuss the major challenges in PV-PEC integration and outline the major breakthroughs in design and materials development for high Solar to Hydrogen (STH) efficiency and long device lifetime. The importance of material selection and metal-oxide semiconductor nanostructures for PV-PEC integration are also discussed with a special focus on Cu-oxide as an emerging material. An outlook toward commercialization including the major guiding factors and related technologies (for e.g., PV-Thermal integration) that can maximize solar energy utilization to reduce payback time has been discussed.

We have investigated the electronic structure and electrical properties of sputter-deposited high-k dielectrics grown on p-GaAs substrate with post-deposition annealing at 500 °C/N 2 ambient. Capacitance-voltage results show that co-sputtered amorphous-HfTiO 2 alloy dielectric can reduce interfacial dangling bonds. HRTEM and AR- X-ray photoelectron spectroscopy results confirmed the formation of a thin interfacial layer during sputter deposition. At the atomistic level, the surface reaction and electronic interface structure were investigated by density-functional theory (DFT) calculations. Using the HSE functional, theoretical calculations of bulk HfO 2, a-TiO 2, and HfTiO 2 band gaps are found to be 5.27, 2.61, and 4.03 eV, respectively. Consequently, in the HfTiO 2 /GaAs interface, the valance band offset is found to be reduced to 1.04 eV compared to HfO 2 /GaAs structure valance band offset of 1.45 eV. Reduction in border trap density (~10 11 V/cm 2 ) was observed due to Ti atoms bridging between As-dangling bonds. The angle-resolved XPS analysis further confirmed Ti-O-As chemical bonding with very thin (~20 Å) dielectric layers.

Nanoclusters possess an ultrasmall size, amongst other favorable attributes, such as a high fluorescence and long-term colloidal stability, and consequently, they carry several advantages when applied in biological systems for use in diagnosis and therapy. Particularly, the early diagnosis of diseases may be facilitated by the right combination of bioimaging modalities and suitable probes. Amongst several metallic nanoclusters, copper nanoclusters (Cu NCs) present advantages over gold or silver NCs, owing to their several advantages, such as high yield, raw abundance, low cost, and presence as an important trace element in biological systems. Additionally, their usage in diagnostics and therapeutic modalities is emerging. As a result, the fluorescent properties of Cu NCs are exploited for use in optical imaging technology, which is the most commonly used research tool in the field of biomedicine. Optical imaging technology presents a myriad of advantages over other bioimaging technologies, which are discussed in this review, and has a promising future, particularly in early cancer diagnosis and imaging-guided treatment. Furthermore, we have consolidated, to the best of our knowledge, the recent trends and applications of copper nanoclusters (Cu NCs), a class of metal nanoclusters that have been gaining much traction as ideal bioimaging probes, in this review. The potential modes in which the Cu NCs are used for bioimaging purposes (e.g., as a fluorescence, magnetic resonance imaging (MRI), two-photon imaging probe) are firstly delineated, followed by their applications as biosensors and bioimaging probes, with a focus on disease detection.

Morphological changes of copper oxide (CuO) nano-structures have been studied in detail for renewable energy and electronic applications. The CuO nano-structures were grown on a silicon substrate via a two-stage process starting with radio frequency sputtering for the seed layer followed by chemical bath deposition. The study was focused on controlling the shape and size of the CuO nano-structures depending on various growth conditions, such as reaction time, growth temperature, and vertical/horizontal orientation of the substrate containing the sputtered-grown seed layer. Structural, optical, crystallographic, and morphological characteristics of the nano-structures were obtained through field-emission scanning electron microscopy, x-ray diffraction crystallographic analysis, and UV–Vis spectroscopy.

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Acute myeloid leukemia (AML) is characterized by relapse and treatment resistance in a major fraction of patients, underlining the need of innovative AML targeting therapies. Here we analysed the therapeutic potential of an innovative biohybrid consisting of the tumor-associated peptide somatostatin and the photosensitizer ruthenium in AML cell lines and primary AML patient samples. Selective toxicity was analyzed by using CD34 enriched cord blood cells as control. Treatment of OCI AML3, HL60 and THP1 resulted in a 92, and 99 and 97% decrease in clonogenic growth compared to the controls. Primary AML cells demonstrated a major response with a 74 to 99% reduction in clonogenicity in 5 of 6 patient samples. In contrast, treatment of CD34 CB cells resulted in substantially less reduction in colony numbers. Subcellular localization assays of RU-SST in OCI-AML3 cells confirmed strong co-localization of RU-SST in the lysosomes compared to the other cellular organelles. Our data demonstrate that conjugation of a Ruthenium complex with somatostatin is efficiently eradicating LSC candidates of patients with AML. This indicates that receptor mediated lysosomal accumulation of photodynamic metal complexes is a highly attractive approach for targeting AML cells.

Cupric oxide (CuO) is a promising candidate as a photocathode for visible-light-driven photo-electrochemical (PEC) water splitting. However, the stability of the CuO photocathode against photo-corrosion is crucial for developing CuO-based PEC cells. This study demonstrates a stable and efficient photocathode through the introduction of graphene into CuO film (CuO:G). The CuO:G composite electrodes are prepared using graphene-incorporated CuO sol–gel solution via spin-coating techniques. The graphene is modified with two different types of functional groups, such as amine (-NH) and carboxylic acid (-COOH). The -COOH-functionalized graphene incorporation into CuO photocathode exhibits better stability and also improves the photocurrent generation compare to control CuO electrode. In addition, -COOH-functionalized graphene reduces the conversion of CuO phase into cuprous oxide (CuO) during photo-electrochemical reaction due to effective charge transfer and leads to a more stable photocathode. The reduction of CuO to CuO phase is significantly lesser in CuO:G-COOH as compared to CuO and CuO:G-NH photocathodes. The photocatalytic degradation of methylene blue (MB) by CuO, CuO:G-NH and CuO:G-COOH is also investigated. By integrating CuO:G-COOH photocathode with a sol–gel-deposited TiO protecting layer and Au–Pd nanostructure, stable and efficient photocathode are developed for solar hydrogen generation.

This chapter discusses about recent advancements on smart coating and their potential applications in smart window engineering. First part of this book-chapter will discuss about recent developments in Smart-window technology. It has potential to exhibit different applications using various sources such as light, heat, and voltage to produce unique properties. In comparison to normal static windows, smart windows can modulate solar transmittance of NIR and visible light depending on weather conditions and personal preferences of human beings inside the door. Although very few smart windows are commercially available in the market, their demand is not yet to be realized. On the other hand, latest engineered nanostructured materials contribute new opportunities for future smart window technology. Initially, this article will elaborate the antibacterial activities of smart coating technology. Antibacterial surfaces are of great importance due to their potential application in coating of medical devices and implants, paints, food packaging, transportation etc. Final section of this chapter will illustrate wettability research done on novel material surfaces including smart windows. Understanding solid–liquid interface at fundamental level is of tremendous implication due to their potential application in creating self-cleaning and self-lubricating surfaces. These types of advanced thin film surfaces can have multiple potential applications ranging from everyday life to advanced technological utilization such as transparent coating of smart windows to microfluidics to fabrication of advanced nano-biomaterials.

The development of sensitive biosensors, such as gallium nitride (GaN)-based quantum wells, transistors, etc., often makes it necessary to functionalize GaN surfaces with small molecules or eVen biomolecules, such as proteins. As a first step in surface functionalization, we have investigated silane adsorption, as well as the formation of very thin silane layers. In the next step, the immobilization of the tetrameric protein streptavidin (as well as the attachment of chemically modified iron transport protein ferritin (ferritin-biotin-rhodamine complex)) was realized on these films. The degree of functionalization of the GaN surfaces was determined by fluorescence measurements with fluorescent-labeled proteins; silane film thickness and surface roughness were estimated, and also other surface sensitive techniques were applied. The formation of a monolayer consisting of adsorbed organosilanes was accomplished on Mg-doped GaN surfaces, and also functionalization with proteins was achieved. We found that very high Mg doping reduced the amount of surface functionalized proteins. Most likely, this finding was a consequence of the lower concentration of ionizable Mg atoms in highly Mg-doped layers as a consequence of self-compensation effects. In summary, we could demonstrate the necessity of Mg doping for achieving reasonable bio-functionalization of GaN surfaces.