Search

Purpose: The antibacterial properties of silver nanoparticles (AgNPs) are extensively identified. In large quantities, they might be harmful. So many fields of nanotechnology have shown a great deal of interest in the development of an environmentally friendly, efficient method for synthesizing metal nanoparticles. Because of its antibacterial and antifungal properties toward a wide range of microbes, chitosan silver nanoparticles (AgNPs@Cs) constitute a newly developing class of bio-nanostructured hybrid materials. Furthermore, the use of photothermal therapy (PTT) has been suggested as a means of elimination of germs. These light-stimulated treatments are minimally invasive and have a few side effects. In the present work, the antibacterial effect of AgNPs at low concentrations; prepared by chemical and green methods as antimicrobial and photothermal agents in photothermal therapy; with laser irradiation were explored as combined treatment against MRSA, Pseudomonas aeruginosa, and Klebsiella pneumoniae. Methods: Silver nanoparticles were produced in two ways. First, by sodium borohydrides, second, by chitosan (as a natural eco-friendly reducing, and capping agent). The nanostructure of AgNPs and AgNPs@Cs was confirmed by UV–visible spectrometer, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIRs), and direct light scattering (DLS). The antibacterial activity of the prepared nanoparticles and the laser irradiation was tested against three bacterial species of zoonotic importance; MRSA, Pseudomonas aeruginosa, and Klebsiella pneumoniae; and was evaluated by measuring their minimum inhibitory concentrations (MIC). Results: Silver nanoparticles produced by the two methods had spherical shapes with nearly the same particle size. The analysis of DLS showed that AgNPs were very stable with zeta potential − 28.8 mv, and 47.7 mv by chemical and chitosan synthesis, respectively. Furthermore, AgNPs@Cs showed higher antibacterial activity toward the tested bacterial species than AgNPs by chemical method. Additionally, the bacterial viability using photothermal laser therapy was reduced compared to laser and AgNPs alone. The bactericidal activities were higher when laser diode was coupled with AgNPs@Cs than by chemical reduction. Conclusion: The laser combined treatment had a higher antimicrobial effect than AgNPs alone or laser irradiation alone. [ABSTRACT FROM AUTHOR]

Materials based on hybrid bimetallic particles with a polyacrylamide shell can act as an efficient centers of energy dissipation in filled composites and reveal more effectiveness than nanoparticles, which, due to their higher surface-to-volume ratio and low interfacial adhesion, can affect the final composite performance. Two types of fillers were obtained as part of polymer-mediated synthesis and subsequent thermolysis and later encapsulated into a LDPE matrix. The metal-polymer complex increases the damping capacity of the hosting material up to 25% at higher concentration. However, the nanoparticles showed a strong increase at 5 wt% (by 20%) and then a sharp decline, which makes metal-polymer particles more suitable for damping purposes. [ABSTRACT FROM AUTHOR]

Presently, the creation of metal nanoparticles (NPs) using plant extracts has rapidly gained an appealing aspect in the realm of modern nanobiotechnology, with substantial merits over traditional techniques. In this context, cadmium oxide (CdO) NPs have been created utilizing a bio-inspired green synthetic approach using Citrus limetta peel extract. The active organic biomolecules within the peel extract functioned as reductants and stabilizers for NPs, resulting in pure CdO NPs. The structural, chemical, optical, and topological traits were evaluated utilizing XRD, FTIR, FESEM, EDX, HRTEM, UVDRS, and PL analyses. The synthesized CdO NPs are about 54 nm in size with a quasi-spherical morphology. The computed band gap of NPs was 2.59 eV, which validated the cubic phase formation of CdO NPs. The photocatalytic studies of the as-fabricated CdO NPs were investigated through Rhodamine B (RhB) dye degradation via H2O2-assisted AOP under sunlight. The effect of H2O2, photocatalyst loading, RhB dye concentration, contact time, scavengers, and recyclability study was also investigated in detail to demonstrate the functionality of the photocatalyst. Approximately 85% of the dye was decomposed within 60 min, revealing its excellent photocatalytic performance of CdO NPs. Therefore, the research outcomes thus offer that the CdO NPs may have a substantial potential for ecological remediation through a photocatalytic approach. [ABSTRACT FROM AUTHOR]

Metal nanoparticles (MNPs) have gained considerable attention for their diverse applications across various fields, including medicine, electronics, and environmental remediation, agriculture and manufacturing. The relationship between metal nanoparticles and the microorganisms, highlighting the diverse mechanisms through which nanotoxicity manifests and influences microbial communities. Metal nanoparticles, owing to their unique physicochemical properties, can interact with the microbiome directly or indirectly, disrupting microbial homeostasis and functionality. The interactions are complex, involving mechanisms such as membrane disorganization, reactive oxygen species (ROS) generation, and oxidative Deoxyribonucleic acid (DNA) damage. Comprehending the different types of metal nanoparticles, their antimicrobial properties, and the mechanisms that underlie their nanotoxicity towards microorganisms is imperative for the secure advancement and implementation of nanotechnology, paving the way for innovative strategies to mitigate adverse effects and promote sustainable nanomaterial applications. Nanotechnology has witnessed remarkable advancements in various fields, yet concerns regarding its potential adverse effects on biological systems, particularly the microbiome, have emerged as a significant area of investigation. This abstract highlight the importance of interdisciplinary approaches encompassing nanoscience, microbiology, and toxicology to unravel the intricate dynamics of metal nanoparticle-microbes' interactions and facilitate the design of safer nanoproducts for diverse applications. Overall, this study emphasizes the need for more investigation to clarify the complex dynamics of metal nanoparticles in microbial environments and their long-term effects on sustainability and environmental health. [ABSTRACT FROM AUTHOR]

Ciprofloxacin (CIPH) was classified as one of the most effective quinolone antibiotics, which is commonly used to cure a wide range of infections resulting from Gram-negative and Gram-positive microorganisms. The complexes which formed due to the interaction of Ni(II), Zn(II), Cu(II), Gd(III) and Sm(III) with ciprofloxacin were characterized by CHN% analysis, conductivity, FTIR, electronic spectra, fluorescence measurements, and magnetic susceptibility, besides studying the complex–DNA interaction. Meanwhile, the molar conductance values (0.001 mol·L−1 in DMSO) revealed the electrolytic behavior of the complexes and could be designated with the A−B+ formula. In addition, the geometry of the compounds was confirmed from the electronic transitions as well as the μeff values as octahedral for all complexes. The postulated formula could be generally assigned as [M(CIP)a(CIPH)b(H2O)c](NO3)(H2O)n(C2H5OH)m. Moreover, the interaction between metal complexes and DNA revealed that the Cu complex had the highest binding constant. Nanotechnology was applied to synthesized compounds using silica nanoparticles (SiNPs), which were prepared using a sol–gel process. The silica nanoparticles were chemically functionalized for binding the ligand and its metal complexes; this enables the as-prepared compounds to enhance their features as a drug delivery platform. Meanwhile, the antimicrobial activity was tested for the free complexes and SiNPs composites. Collectively, Sm complex gave the largest zone of inhibition, while the Cu(II)–SiNPs composite showed the strongest potential to reduce the bacterial activity. Furthermore, the fluorescence data of CIPH, ligand–metal mixture and the effect of silica nanoparticles on them were studied. [ABSTRACT FROM AUTHOR]

Bacteriocins are antimicrobial peptides produced by bacteria to prevent the growth of pathogens. Combining bacteriocins with metal nanoparticles, like silver nanoparticles (AgNPs), has developed into a viable strategy to get over bacteriocin limitations. In this study, bacteriocin BacZY05 was extracted from Bacillus subtilis ZY05 and purified using various techniques. The resulting purified bacteriocin was then combined with silver nanoparticles to form bacteriocin silver nanoconjugates (BacZY05-AgNPs). The physicochemical properties of the BacZY05-AgNPs were characterized using various analytical techniques. The mean diameter of the synthesized AgNPs was approximately 20–60 nm with an oval or spherical shape. The antimicrobial activity of the BacZY05-AgNPs was evaluated against several indicator strains by their zone of inhibition (ZOI), using the agar well diffusion method. Compared to bacteriocin (ZOI- 13 to 20 mm) and AgNPs (ZOI- 10–22 mm) alone, the antibacterial activity data demonstrated a 1.3-1.5-fold increase in the activity of bacteriocin-nanoconjugates (ZOI- 22 to 26 mm). For Staphylococcus aureus MTCC3103 and Klebsiella pneumoniae MTCC109, BacZY05-capped AgNPs exhibited the lowest minimum inhibitory concentration (MIC), measuring 10.93 µg/mL. For Salmonella typhi NCIM2501, the MIC was 28.75 µg/mL. The highest MIC value was 57.5 µg/mL for Escherichia coli DH5α and Vibrio cholerae MTCC3909. With BacZY05-capped AgNPs, the lowest minimum bactericidal concentration (MBC) of 28.75 µg/mL was observed for Staphylococcus aureus MTCC31003. In the cases of Salmonella typhi NCIM2501 and Klebsiella pneumoniae MTCC109 concentration was 57.5 µg/mL. Vibrio cholerae MTCC3909 and Escherichia coli DH5α had the highest MBC values at 115 µg/mL. [ABSTRACT FROM AUTHOR]

Purpose: The treatment of amoebic infections is often problematic, largely due to delayed diagnosis, amoebae transformation into resistant cyst form, and lack of availability of effective chemotherapeutic agents. Herein, we determined anti-Acanthamoeba castellanii properties of three metal oxide nanoparticles (TiO2, ZrO2, and Al2O3). Methods: Amoebicidal assays were performed to determine whether metal oxide nanoparticles inhibit amoebae viability. Encystation assays were performed to test whether metal oxide nanoparticles inhibit cyst formation. By measuring lactate dehydrogenase release, cytotoxicity assays were performed to determine human cell damage. Hoechst 33342/PI staining was performed to determine programmed cell death (apoptosis) and necrosis in A. castellanii. Results: TiO2-NPs significantly inhibited amoebae viability as observed through amoebicidal assays, as well as inhibited their phenotypic transformation as evident using encystation assays, and showed limited human cell damage as observed by measuring lactate dehydrogenase assays. Furthermore, TiO2-NPs altered parasite membranes and resulted in necrotic cell death as determined using double staining cell death assays with Hoechst33342/Propidium iodide (PI) observed through chromatin condensation. These findings suggest that TiO2-NPs offers a potential viable avenue in the rationale development of therapeutic interventions against Acanthamoeba infections. [ABSTRACT FROM AUTHOR]

The low signal-to-noise ratio (S/N) and single functionality of fluorescence imaging agents have limited their practical applications. Bright two-photon excitation (2PE) imaging probes are highly desirable in vivo with larger imaging depth, minor autofluorescence background, and less photodamage. Herein, we developed responsive aggregated gold nanoparticles (Au NPs) as high contrast 2PE imaging agents, capable of emitting red fluorescence upon excitation of near-infrared (NIR) laser and possessing a high signal-to-noise ratio (S/N of 2,475). By forming aggregates in situ inside tumor tissue, doxorubicin hydrochloride (DOX)-loaded mix-charged gold nanoparticles (DOX-MC-Au NPs) were utilized to act as selective fluorescence imaging probes and precise therapy agents. These high-contrast theranostic agents offer a promising potential for precise cancer imaging and therapy, which might open a new venue to multifunctional and noninvasive theranostics. [ABSTRACT FROM AUTHOR]

The utilization of synthetic plastics has resulted in environmental and human health concerns. Consequently, there is a growing focus on developing eco-friendly alternatives like polylactic acid (PLA). Nonetheless, its drawbacks include slow crystallization, vulnerability to UV radiation, and absence of antibacterial properties. One potential strategy involves integrating nano-cellulose (NC) and metal oxide nanoparticles into PLA to enhance its antibacterial features and mechanical robustness. The NC was extracted from the leaves of Borassus flabellifer and further treated with lactic acid to obtain surface-modified NC (SMNC). Besides, the Zinc oxide nanoparticles (ZnO NPs) were green-synthesized using the B. flabellifer leaves extract and further characterized through various analytical techniques such as SEM, XRD, and FTIR. The optimized bio-composite ratio was 89.5 mg of PLA, 3.5% (w% of PLA) of SMNC, and 7% (wt% of PLA) of ZnO NPs based on the appearance, water contact angle (WCA), and antimicrobial activities of the bio-composite film. The PLA-SMNC-ZnO NPs film was further characterized and compared with PLA and PLA-SMNC films for its structural, mechanical, and thermal properties. The PLA-SMNC- ZnO NPs film exhibited an improved tensile strength of 13.9 MPa and Young's modulus of 0.00689 GPa than PLA and PLA-SMNC. Also, the thermal stability of PLA-SMNC-ZnO NPs film was 320 °C from TGA. Additionally, PLA-SMNC- ZnO NPs film exhibited reduced water absorption and improved resistance to UV radiation. In conclusion, these findings validate the potential of the ZnO NPs derived from B. flabellifer's leaves in improving the versatility of PLA. [ABSTRACT FROM AUTHOR]

Biopolymers embedded with nanoparticles of metal oxides (MOs) demonstrate a wide range of bio-functions. Chitosan-incorporated MOs are an interesting class of support matrices for enhancing the biological function, compared to other support matrices. Therefore, the importance of this study lies in exploiting chitosan as a carrier not of one metal as in previous studies, but of two metals in the form of a nanocomposite to carry out several biological functions. The coprecipitation approach was employed to synthesize chitosan/Fe2O3/ZnO-nanocomposite in the present research. The characterization of chitosan/Fe2O3/ZnO-nanocomposite was performed to find out the morphology and dispersion properties of chitosan/Fe2O3/ZnO-nanocomposite. The X-ray diffraction (XRD) investigation revealed that these were crystalline. Fourier transforms infrared (FTIR) spectrum bands were viewed at 400/cm and 900/cm, due to the stretching vibration of Fe and Zn oxygen bond. TEM showed that chitosan/Fe2O3/ZnO-nanocomposite was of 20–95 nm in size. chitosan/Fe2O3/ZnO-nanocomposite exhibited inhibitory potential against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Candida albicans with inhibition zones of 25 ± 0.1, 28 ± 0.2, 27 ± 0.1, and 27 ± 0.2 mm, respectively while didn't inhibited Aspergillus niger. MIC value of nanocomposite was 15.62 ± 0.33 µg/mL for C. albicans, B. subtilis and E. coli, while it was 62.50 ± 0.66 µg/mL for Pseudomonas aeruginosa. Ranged values of nanocomposite MBC (15.62 ± 0.33 to 125 ± 1 µg/mL) were attributed to all tested bacteria. Different concentrations of chitosan/Fe2O3/ZnO-nanocomposite MBC (25, 50, and 75%) reflected anti-biofilm activity against E. coli (85.0, 93.2, and 96.0%), B. subtilis (84.88, 92.21, and 96.99%), S. aureus 81.64, 90.52, and 94.64%) and P. aurogenosa (90.11, 94.43, and 98.24%), respectively. The differences in the levels of antimicrobial activities may depend on the type of examined microbes. Antioxidant activity of chitosan/Fe2O3/ZnO-nanocomposite was recorded with excellent IC50 values of 16.06 and 32.6 µg/mL using DPPH and ABTS scavenging, respectively. Wound heal by chitosan/Fe2O3/ZnO-nanocomposite was achieved with 100% compared to the untreated cells (76.75% of wound closer). The cytotoxicity outcomes showed that the IC50 of the chitosan/Fe2O3/ZnO-nanocomposite was 564.32 ± 1.46 µg/mL normal WI-38 cells. Based on the achieved findings, the chitosan/Fe2O3/ZnO-nanocomposite is a very promising agent for perform pharmacological activities. [ABSTRACT FROM AUTHOR]

The synthesis of metal nanoparticles through bio-reduction is environmentally benign and devoid of impurities, which is very important for biological applications. This method aims to improve ZnO nanoparticle's antibacterial and anti-biofilm activity while reducing the amount of hazardous chemicals used in nanoparticle production. The assembly of zinc oxide nanoparticles (ZnO NPs) is presented via bio-reduction of an aqueous zinc nitrate solution using Echinochloacolona (E. colona) plant aqueous leaf extract comprising various phytochemical components such as phenols, flavonoids, proteins, and sugars. The synthesized nano ZnO NPs are characterized by UV–visible spectrophotometer (UV–vis), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (X-RD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and elemental composition by energy-dispersive x-ray spectroscopy (EDX). The formation of biosynthesized ZnO nanoparticles was confirmed by the absorbance at 360–370 nm in the UV–vis spectrum. The average crystal size of the particles was found to be 15.8 nm, as calculated from XRD. SEM and TEM analysis of prepared ZnO NPs confirmed the spherical and hexagonal shaped nanoparticles. ZnO NPs showed antibacterial activity against Escherichia coli and Klebsiella pneumoniae with the largest zone of inhibition (ZOI) of 17 and 18 mm, respectively, from the disc diffusion method. Furthermore, ZnO NPs exhibited significant anti-biofilm activity in a dose-dependent manner against selected bacterial strains, thus suggesting that ZnO NPs can be deployed in the prevention of infectious diseases and also used in food preservation. [ABSTRACT FROM AUTHOR]

Controlling the precise growth of atoms is necessary to achieve manipulation of atomic composition and atomic position, regulation of electronic structure, and an understanding of reactions at the atomic level. Herein, we report a facile method for ordered anchoring of zero-valent platinum and manganese atoms with single-atom thickness on graphdiyne under mild conditions. Due to strong and incomplete charge transfer between graphdiyne and metal atoms, the formation of metal clusters and nanoparticles can be inhibited. The size, composition and structure of the bimetallic nanoplates are precisely controlled by the natural structure-limiting effect of graphdiyne. Experimental characterization clearly demonstrates such a fine control process. Electrochemical measurements show that the active site of platinum-manganese interface on graphdiyne guarantees the high catalytic activity and selectivity (~100%) for alkene-to-diol conversion. This work lays a solid foundation for obtaining high-performance nanomaterials by the atomic engineering of active site. This work reports a facile method for growing highly ordered Pt and Mn bimetallic single atomic layers on graphdiyne. This fully activates loaded metal atoms and results in in high activity and selectivity for electrocatalytic alkene-to-diol conversion [ABSTRACT FROM AUTHOR]

Improved measurement and analysis technologies are needed for investigating nanoparticle generation characteristics in sewage treatment plants. Single-particle inductively coupled plasma–mass spectrometry (spICP-MS) can be used to analyze metal nanoparticle characteristics. However, during spICP-MS analysis of environmental samples, high concentrations of ionic materials obscure the signals of particulate materials by increasing background signals. This can increase the threshold value for separating background and particle signals and increase the background-equivalent diameter (BED). In this study, particle size distributions in influent and effluent collected from sewage treatment plants were investigated using an improved spICP-MS method combining spICP-MS with ion-exchange resin (IER) column pretreatment. The ion removal effect of the IER column was first examined using a synthetic mixture of Ag nanoparticles (AgNPs) and ions. The method was then applied to wastewater from six different sewage treatment plants using an optimal IER packing of 5 g. The ion removal efficiency for samples containing a proper mixture of AgNPs and Ag ions was 99.98%, and the BED significantly decreased from 73.0 ± 1.0 to 6.1 ± 0.3 nm. Particle size distributions measured in the treatment plant influent and effluent ranged from 28.5 nm (Co) to 220.3 nm (Mg) and from 26.8 nm (Co) to 291.8 nm (Mg), respectively. spICP-MS/IER enabled the detection of smaller particles by removing ions from the sample and significantly decreasing the size detection limit. The results of this study offer a reference for developing predictive models for removing metal nanoparticles during sewage/wastewater treatment. [ABSTRACT FROM AUTHOR]

Noble metal nanoparticles incorporated in hybrid nanocomposites are considered as promising candidates for electrochemical applications owing to their physicochemical properties. In this work, we demonstrated the preparation of Fe2O3/rGO nanocomposite by hydrothermal method, followed by in situ Ag binding synthesis for the fabrication of hybrid nanocomposite (Ag/α-Fe2O3/rGO). The crystallographic structure of the hybrid nanocomposite is examined by X-ray diffraction (XRD) analysis which confirms the characteristics of Ag, Fe2O3, and rGO. The microscopic studies and energy-dispersive X-ray analysis (EDS) spectra confirmed the presence and formation of hybrid nanostructures. Raman analysis results further corroborate the formation of composite with significant D and G bands in Fe2O3/rGO and Ag/α-Fe2O3/rGO samples, which follow XRD results. Cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) studies were carried out to analyze the faradaic capacitor behavior. A specific capacitance of 209.09 F/g was observed by GCD studies for Ag/α-Fe2O3/rGO composites at a current density of 1 A/g, which exhibited good capacitance retention of 94% for 5000 cycles at 7 A/g. Furthermore, the Ag/α-Fe2O3/rGO electrode was used for the electrochemical detection of nitrate ions in soil by utilizing an ion-selective membrane over the surface of the Ag/α-Fe2O3/rGO electrode. The fabricated nanocomposite electrode showed a significant change in the peak current values with the concentration of nitrate in a linear range from 10 to 450 μM with the sensitivity to be calculated 1.426 μA μM−1 cm−2 and limit of detection (LOD) calculated to be 0.18 μM. The reproducibility and interference studies showed a promising result to be utilized for detecting nitrate ions in soil and in real-time applications. [ABSTRACT FROM AUTHOR]

Due to the rising human population and industrialization, harmful chemical compounds such as 4-nitrophenol (4-NP) and various dyes are increasingly released into the environment, resulting in water pollution. It is essential to convert these harmful chemicals into harmless compounds to mitigate this pollution. This research focuses on synthesizing a novel heterogeneous catalyst using modified canvas fabric (CF) decorated with silver metal nanoparticles on graphene oxide nanosheets (Ag-GO/CF). The process involves coating the fabrics (CF) with graphene oxide (GO) nanosheets through sonication. Subsequently, silver nanoparticles are deposited in situ and reduced on the GO surface, resulting in the formation of the Ag-GO/CF composite. Various physicochemical characterizations were conducted to examine the interfacial interactions between CF, GO, and Ag nanoparticles. The catalytic activity of the nanocomposite was assessed by hydrogenating 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of sodium borohydride (NaBH4). The results showed that the 10%Ag-5%GO/CF with a surface of 6 cm2 (3 × 2 cm) exhibited the highest catalytic activity, achieving a reduction efficiency of over 96% in 5 min. The 4-NP reduction reaction rate was well-fitted with a pseudo-first-order kinetics model with an apparent reaction rate constant (Kapp) of 0.676 min−1. Furthermore, the Ag-GO/CF composite demonstrated remarkable stability over successive cycles, with no noticeable decrease in its catalytic activity, suggesting its promising application for long-term chemical catalytic processes. This synthesized composite can be easily added to and removed from the reaction solution while maintaining high catalytic performance in the reduction of 4-NP, and it could be beneficial in avoiding problems related to powder separation. [ABSTRACT FROM AUTHOR]

The review study was carried out to investigate the effect of metal oxide (MO) nanoparticles on the characteristics of a polymeric matrix. Polyaniline, more commonly known as PANI, is one of the most addressed intrinsically conducting polymers. PANI was chosen as a promising conducting polymer among the competition and its application range was expanded by combining it with various components, including graphene, graphene oxide, metal oxide, carbon, carbon nanotubes, silicon, silicon dioxide, biomolecules, and metal–organic frameworks. This review illustrates how polyaniline can be doped with metal oxide nanoparticles notably Al2O3, CeO2, CuO, NiO, TiO2, and ZnO. Furthermore, the synthesis, characteristics, and applications of PANI metal oxide nanocomposites were also addressed. Since metal oxides (MO) already have a wide range of applications, combining PANI with MO can create a world of opportunity. An effort has been attempted in order to bring close enough to the recently focused study field of PANI-MO nanocomposites. [ABSTRACT FROM AUTHOR]

Two-dimensional materials possessing intrinsic multiferroic properties have long been sought to harness the magnetoelectric coupling in nanoelectronic devices. Here, we report the achievement of robust type I multiferroic order in single-layer chromium trihalides by decorating transition metal atoms. The out-of-plane ferroelectric polarization exhibits strong atomic selectivity, where 12 of 84 single-layer transition metal-based multiferroic materials possess out-of-plane ferroelectric or antiferroelectric polarization. Group theory reveals that this phenomenon is strongly dependent on p–d coupling and crystal field splitting. Cu decoration enhances the intrinsic ferromagnetism of trihalides and increases the ferromagnetic transition temperature. Moreover, both ferroelectric and antiferroelectric phases are obtained, providing opportunities for electrical control of magnetism and energy storage and conversion applications. Furthermore, the transport properties of Cu(CrBr3)2 devices are calculated based on the non-equilibrium Green's function, and the results demonstrate outstanding spin-filtering properties and a low-bias negative differential resistance (NDR) effect for low power consumption. [ABSTRACT FROM AUTHOR]

The study describes the successful development of a TiO2 ceramic substrate with a protective nano-Al2O3 coating using two different coating techniques: microwave combustion and polymeric methods. The coated ceramics demonstrate enhanced corrosion resistance compared to the uncoated substrate. The optimal TiO2 substrate was prepared by firing it at 1000 °C. This was done to give the desired physical properties of the TiO2 substrate for the coating procedures. Nano-Al2O3 powder was coated onto the surface of the TiO2 substrates. The TiO2 substrates with the Al2O3 coating were then calcined (heat-treated) at 800 and 1000 °C. The structures, morphology, phase composition, apparent porosity, bulk density, and compressive strength of the substrate and coated substrate were characterized. Upon firing at 1000 °C, it was discovered that the two phases of TiO2—rutile and anatase—combine in the substrate. Once the substrate has been coated with nano Al2O3 at 1000 °C, the anatase is transferred into rutile. When compared to the substrate, the coated substrate resulted in a decrease in porosity and an increase in strength. The efficiency of the ceramic metal nanoparticles Al2O3 as a good coating material to protect the TiO2 substrates against the effect of the corrosive medium 0.5 M solution of H2SO4 was measured by two methods: potentio-dynamic polarization (PDP) and the electrochemical impedance spectroscopy (EIS). The results indicated that the corrosion rate was decreased after the substrate coated with alumina from (67.71 to 16.30 C.R. mm/year) and the percentage of the inhibition efficiency recorded a high value reaching (78.56%). The surface morphology and composition after electrochemical measurements are investigated using SEM and EDX analysis. After conducting the corrosion tests and all the characterization, the results indicated that the coated TiO2 substrate prepared by the polymeric method at 800 °C displayed the best physical, mechanical, and corrosion-resistant behavior. [ABSTRACT FROM AUTHOR]

The application of phyto-nanotechnology in horticulture is a sustainable tool for agriculture due to its cost-effectiveness and eco-friendly properties. Essential micro-elements have been used as nano-fertilizer to enhance crop production. Fine-tuning of the nanoparticle dose is also recognized as the critical factor determining their impact on plant growth. Therefore, this study aimed to investigate the effects of iron (Fe) and manganese (Mn) oxide nanoparticles (NPs) on potato plants physiological and biochemical changes under the hydroponic conditions. Observations revealed that the plant growing in the adapted hydroponics media (supplemented with 4.0 mg L− 1 Fe3O4 NPs and 1.0 mg L− 1 MnO2 NPs instead of original Fe and Mn salt respectively) improved various physiological and biochemical parameters, total biomass, and tuber yield compared to the untreated control. The growth-promoting impact of metal oxide NPs (hereafter refers as MONPs) simultaneously induced the activity of various antioxidant enzymes (SOD, CAT, POD) and contributed to the adequate reduction in malondialdehyde (MDA) and hydrogen peroxide (H2O2) content relative to the untreated control plants. This indicated that the application of MONPs could improve the potato yield per plant via modulating the plant antioxidant machinery. In addition, the application of MONPs as nano-nutrient appreciably improved the photosynthetic efficiency of plants via modulating the photosynthetic pigment content like Chl a, Chl b, total Chl, ratio Chl a/b, carotenoids as well as soluble sugar. The SEM-EDX elemental mapping also showed a slightly higher content of metals ions (Fe, Mn, and Ca) in the root and shoot tissues, however, the TEM analysis also confirmed absorption as well as transportation of MONPs in the root tissues growing in the presence of MONPs. This study opened the opportunity of utilizing MONPs as nano-nutrient in a hydroponic condition for development of pathogen-free potato tuber. [ABSTRACT FROM AUTHOR]

The current study demonstrates an easy utilization of glycine soja sensu auct green extract as a power source for the desired synthesis of copper oxide (CuO) nanoparticles via green synthesis process to acquire significant detection of hydrogen peroxide (H2O2) and monosaccharide glucose through an uncomplicated colorimetric method. Due to sustainability issues, synthesis of the metal or metal oxide nanoparticles has shifted towards eco-safe reducing agents. This research focuses on the utilization of the reducing agent via green technology, namely glycine soja sensu auct extract, for the synthesis of CuO nanoparticles by co-precipitation synthesis. Through XRD studies, it can be depicted that the material is monoclinic. FESEM and HRTEM images reveals spherical shape of nanoparticles. HRTEM images also indicate that the size of the particles falls between 10–30 nm. The particle distribution curve reveals the z-average size of 135.1 nm. The Fourier transform infrared spectroscopy peak at 493.14, 522.01, 557.89 and 649.39 cm-1 refer to the vibrations between Cu and O. Clearly, the peaks indicate the formation of CuO nanostructure. These green CuO NPs successfully catalyzed the oxidation reaction of the exposed peroxidase substrate 3, 3′, 5, 5′- tetramethylbenzidine (TMB) dye by hydrogen peroxide (H2O2) to develop a bluish colour reaction with the absorption maxima centred at 652 nm. The CuO NPs exhibited better kinetics over horseradish peroxidase (HRP), the natural enzyme, with a lower Km value. Linear response range for glucose, was 10 – 100 µM and a limit of detection (5.06 µM) was obtained. [ABSTRACT FROM AUTHOR]

Palladium nanoparticles (PdNPs) have emerged as promising metal nanoparticles in biomedical applications. In particular, green-synthesized PdNPs have gained significant attention due to their advantages of being simple, cost-effective, and low-toxic. This review summarizes the green synthesis of medicinal-oriented PdNPs using natural sources such as plants, mushrooms, algae, fungi, and biological molecules. Furthermore, this review discusses the potential biomedical applications of these green-synthesized PdNPs such as photothermal therapy, antibacterial/antitumor therapies, drug delivery, and imaging. It also identifies the current challenges and prospects for their use in these applications. Overall, this review demonstrates the promising potential of biogenic PdNPs for biomedical applications and provides valuable insights for future research in this field. [ABSTRACT FROM AUTHOR]

Over the past few years, there has been an increasing fascination with environmentally conscious techniques for the synthesis of nanoparticles, due to the drawbacks associated with conventional methodologies. These conventional methods frequently depend on the utilization of hazardous chemical substances and yield substantial waste, resulting in detrimental ecological contamination. As a result, alternative strategies utilizing plants and microorganisms such as bacteria, fungi, algae, and their metabolites have gained attention. Microbial pigments (MPs) have gained significant attention in recent years due to their versatile bioactivities. This field of research combines the unique properties of MPs with the diverse applications of metal nanoparticles (MNPs), resulting in a range of promising outcomes. In microbial pigment-mediated nanoparticles (MP-MNPs) synthesis, the biological activities, chemical diversity of pigments, solubility in aqueous medium, lower reaction time, and renewable energy account for high rate of MNPs synthesis with divers shapes and sizes along with corresponding applications. Furthermore, it mitigates the use of harmful chemicals and reduces the generation of waste associated with conventional methods. However, care has to be taken to select suitable MPs for MNPs synthesis, such as in terms of solubility, stability, non-toxicity, and extraction of pigment. This review focuses on the utilization of MPs in the fabrication of MNPs, discussing the possible mechanisms and applications of the synthesized nanoparticles. The advantages and limitations of the microbial pigment-mediated synthesis of different MNPs are also summarized in this review. [ABSTRACT FROM AUTHOR]

The access to drinkable water is a critical challenge in the context of the rising urbanization and industrialization, calling for advanced technologies to clean contaminated waters and wastewater. Here we review the use of metal oxides biochar composites to treat pollution by hevay metals and dyes. We focus on the synthesis of metal oxide nanobiochar; the treatment of pollution by mercury, lead, methylene blue and methyl orange; life cycle analysis; and techno-economical assessment. Metal oxide nanoparticles can act as photocatalysts to allow for the complete mineralization of organic pollutants. For instance, the doping of tin oxide nanoparticles into biochar surface degraded 99.5% of methylene blue dye after 105 min. Ball-milled magnetic nanobiochar achieves 99% mercury removal in 720 min. The presence of biochar enhanced the uptake of contaminants on nanoparticles and facilitated the photocatalytic reaction [ABSTRACT FROM AUTHOR]

Modified composites, blends, polymers and copolymers are some of those engineered materials which are playing a major and remarkable role in achieving our present sustainable environment. Mechanical, electrical, and biological properties of carbon and native metal nanoparticles are distinctive from others and provide plentiful scaffolds for a wide-range of applications in our lives, including medical devices, pharmaceutical, polymer industry, biomedical field, coating of kitchen appliances, food packaging, clothing, gifts, optical devices, biosensors, antimicrobial objects etc. Distinct chemical and physical properties of silver and carbon-based NPs are considered to act in this way. The antimicrobial and conducting nature of Gr and AgNPs are studied here. There is a vast history of these properties; however, beginners still have a bright future. The antimicrobial activity of these two incorporates antibacterial, antifungal, antiviral, anticancer, antioxidant, antistatic and antibiotic nature. Additionally, both nanomaterials exhibit notable thermal conductivity. Based on these characteristics novel composite/blend materials with enhanced electrical, thermal, antimicrobial, antistatic, and antibiotic effect can be engineered with innovative ideas. This paper expresses the worldwide applications of such nanomaterials. [ABSTRACT FROM AUTHOR]

Doping transition metals in ZnO nanoparticles play a vital role in enhancing its photocatalytic activity. (Co,Ni) co-doped ZnO nanoparticles have been synthesized via sol–gel combustion method and explored the impact of co-doping on the structural, optical, morphological and photocatalytic properties of ZnO nanoparticles. The XRD pattern elucidated hexagonal wurtzite structure. The incorporation of co-dopants led to red-shift in the energy band gap. Photoluminescence spectral analysis showed the existence of different defects in the lattice on variation of energization. The assessment for photocatalytic activity was carried out by evaluating the degradation of methylene blue (MB) and rhodamine B (RhB) dyes under sunlight irradiation. Among the photocatalysts, 3%Co–3%Ni showed excellent photocatalytic activity within 75 min. This is in accordance with the decrement in crystallite size, red-shift of band gap, introduction of electron trap levels by the dopants and presence of defects such as oxygen vacancies. Additionally, the calculated CIE co-ordinates of the sample lies in the white region (0.32, 0.32) of CIE diagram and computed CCT were above 5000 K establishing its application in cold white light. [ABSTRACT FROM AUTHOR]

Supported catalyst synthesis involves pretreatment (drying, reduction) of metal complexes to form metal nanoparticles. This study has been undertaken to explore the effect of reduction temperature, heating rate, and water partial pressure on final particle size of Pt and Pd supported on a total of four carbon and oxide supports. Supported nanoparticles were synthesized by strong electrostatic adsorption (SEA) and dry impregnation (DI); the former method was hypothesized to yield greater nanoparticle stability in thermochemical reducing environments stemming from the strong interaction of the precursor with the support during impregnation. Reduced samples were characterized by in-situ and ex-situ XRD and STEM. The DI-derived samples generally showed an expected increase of particle size with increased reduction temperature, and severe particle coalescence in humid hydrogen, while the SEA-derived samples did not sinter at the elevated reduction temperatures (up to 500 °C) and were remarkably stable in the humid reducing environment. [ABSTRACT FROM AUTHOR]

Nanomaterials usually have specific characteristics due to their incredibly tiny size, which also increases their surface area, providing a more interactive surface. Compared to their macro-sized counterparts, these tiny nanoparticles exhibit a multitude of size-dependent properties. Plant tissue culture (PTC) plays an important role in bioactive chemical synthesis, mass cultivation, protection, genetic control, and plant enhancement. Different nanoparticles (NPs) are utilized to improve the tissue culture responses of explants. Various nanoparticles, including cobalt, copper, silver, gold, zinc, selenium, titanium, iron, palladium, cerium, indium, manganese, aluminum, barium, silicon, nickel, zirconium, and their oxides, are used in this regard. Nowadays, it is critical to use nanosystems in conjunction with PTC for mass reproduction, conservation, genetic engineering, crop enhancement, and the synthesis of bioactive compounds. Nanostructured metal oxides play an important role in in vitro plant cultivation. The use of metal nanoparticles (MNPs) has successfully removed microbial contaminants from explants and had a favorable impact on organogenesis (increasing the growth of shoots, roots, and multiplication ratios), callus induction, metabolic changes, and the synthesis of secondary metabolites (NPs are used as elicitors or stress agents). Additionally, NPs cause somaclonal variation (modifications to DNA), improve cryopreservation (increasing the survival rate), and enhance genetic transformation (facilitating gene transformation to bypass the plant cell wall barrier and accelerating protoplast isolation). This review aims to summarize the current breakthroughs achieved by integrating nanotechnology with PTC.Key message: Metal nanoparticles play an important role in in vitro cultures for mass reproduction, conservation, genetic engineering, crop enhancement, and the synthesis of bioactive compounds. [ABSTRACT FROM AUTHOR]

Metal azides are highly energetic materials that release a large amount of gas upon detonation. They also release metal particles, generating an aerosol. The most common azide is sodium azide (NaN3), which is used nowadays in car airbags. If the decomposition is not complete, harmful azide particles might be inhaled. Heavy metal azides find application as a primary explosive (primer) in ammunition. Public health officials have raised concerns about heavy metal particles released during training in shooting ranges. We identify a lack of knowledge on airborne metal particles properties released from azide detonation and on the analytical methods applied to characterize them. As a case study, we detonated milligram amounts of silver azide, copper azide, and a mixture of them in a glove box. We then analyse the airborne particles with an ensemble analytical setup, able to measure real-time their particle size distribution and chemical composition. We detected spherical metal nanoparticles in the range of 2–500 nm. These findings and the developed analytical tools may allow identifying airborne nanoparticles the passenger compartments of vehicles after airbag activation as well as in indoor shooting ranges, contributing to the evaluation of public health risks. [ABSTRACT FROM AUTHOR]

Emulsion liquid membrane (ELM) stands out as an extraction process that has drawn much attention due to its promising prospects in industrial wastewater treatment technology. Nevertheless, the pivotal challenge is to reach high membrane stability to overcome the obstacle of applying ELM at the industrial scale. In this study, ELM was boosted by using nanoparticles (superparamagnetic iron oxide (Fe2O3)) in the stripping phase (W1) and ionic liquid (1-methyl-3-octyl-imidazolium-hexafluorophosphate [OMIM][PF6) in the oil phase (O) for recovering/extracting vanadium from synthetic wastewater to near completion and at the same time enhancing emulsion stability to be appropriate for industrial application. The vanadium recovery/extraction percentage has been raised significantly in 3 min to 99.6% when adding 0.01% (w/w) Fe2O3 NPs (20 to 50 nm in size) in the internal phase (W1) and 5% (v/v) [OMIM]PF6 ionic liquid in the oil phase (O). Also, the emulsion stability was considerably improved, and the leakage percentage was reduced to 16% after 3 days. The results of this study could be used in the future to remove additional heavy metal ions from industrial effluents. [ABSTRACT FROM AUTHOR]

The discrete sources method is used to develop a mathematical model for comparative analysis of the influence exerted on the optical properties of alkaline and noble metal nanoparticles placed in a dense outer medium when the bulk and surface quantum effects are taken into account. A substantial difference between the manifestations of the bulk and surface quantum effects in alkaline particles is demonstrated. Specifically, in the case of the bulk quantum effect, the surface plasmon resonance in alkaline particles exhibits a shift toward shorter wavelengths (blue shift), while the surface effect leads to a shift toward longer wavelengths (red shift). It is shown that this shift depends substantially on the outer medium density and can reach 50 nm in the spectral range. [ABSTRACT FROM AUTHOR]

Cancer is a leading global cause of mortality, which underscores the imperative of early detection for improved patient outcomes. Biorecognition molecules, especially aptamers, have emerged as highly effective tools for early and accurate cancer cell identification. Aptamers, with superior versatility in synthesis and modification, offer enhanced binding specificity and stability compared with conventional antibodies. Hence, this article reviews diagnostic strategies employing aptamer-based biohybrid nano-biosensing technologies, focusing on their utility in detecting cancer biomarkers and abnormal cells. Recent developments include the synthesis of nano-aptamers using diverse nanomaterials, such as metallic nanoparticles, metal oxide nanoparticles, carbon-derived substances, and biohybrid nanostructures. The integration of these nanomaterials with aptamers significantly enhances sensitivity and specificity, promising innovative and efficient approaches for cancer diagnosis. This convergence of nanotechnology with aptamer research holds the potential to revolutionize cancer treatment through rapid, accurate, and non-invasive diagnostic methods. [ABSTRACT FROM AUTHOR]

A novel nitrogen-doped ordered mesoporous carbon (OMC) pore-embedded growth Pt-Ru-Fe nanoparticles (Pt1-Ru7.5-Fex@N-OMCs) composite was designed and synthesized for the first time. SBA-15 was used as a template, and dopamine was used as a carbon and nitrogen source and metal linking reagent. The oxidative self-polymerization reaction of dopamine was utilized to polymerize dopamine into two-dimensional ordered SBA-15 template pores. Iron porphyrin was introduced as an iron source at the same time as polymerization of dopamine, which was introduced inside and outside the pores using dopamine-metal linkage. Carbonization of polydopamine, nitrogen doping and iron nanoparticle formation were achieved by one-step calcination. Then the templates were etched to form Fex@N-OMCs, and finally the Pt1-Ru7.5-Fex@N-OMCs composites were stabilized by the successful introduction of platinum-ruthenium nanoparticles through the substitution reaction. The composite uniformly embeds the transition metal nanoparticles inside the OMC pores with high specific surface area, which limits the size of the metal nanoparticles inside the pores. At the same time, the metal nanoparticles are also loaded onto the surface of the OMCs, realizing the uniform loading of metal nanoparticles both inside and outside the pores. This enhances the active sites of the composite, promotes the mass transfer process inside and outside the pores, and greatly enhances the electrocatalytic performance of the catalyst. The material shows high electrocatalytic performance for adrenaline, which is characterized by a wide linear range, high sensitivity and low detection limit, and can realize the detection of actual samples. [ABSTRACT FROM AUTHOR]

The research on metal oxide nanoparticles (MONs) has witnessed incredible growth in recent decades as they are promising electrode materials for multiple applications. This work presents the hydrothermal synthesis of morphologically different MONs based on zinc, cobalt and cerium metals and their modifications with benzene tricarboxylic acid (BTC) using layer-by-layer assembly method. The simple and modified nanoparticles were structurally characterized by FTIR, XRD, SEM–EDX and TGA. Modified carbon paste electrodes (1% w/w) were fabricated using each of the ZnO, ZnO–Cu–BTC, Co3O4, Co3O4–Cu–BTC, CeO2 and CeO2–Cu–BTC materials separately with graphite powder in paraffin oil using 3 cc portable plastic syringe. The XRD results showed 35.5, 10.8, 14.1, 11.6, 10.2 and 8.6 nm average crystal size for ZnO, ZnO–Cu–BTC, Co3O4, Co3O4–Cu–BTC, CeO2 and CeO2–Cu–BTC, respectively. The electrochemical characterizations of each electrode were performed by EIS as well as CV. The electrochemical surface area of electrodes fabricated from ZnO, ZnO–Cu–BTC, Co3O4, Co3O4–Cu–BTC, CeO2 and CeO2–Cu–BTC materials was calculated to be 153.4, 610.4, 746.1, 951.5, 161.7, and 951.8 cm2, respectively. The results from EIS plots indicated that electrodes based on modified metal oxide nanoparticles experienced lesser charge transfer resistance as compared to that in simple metal oxide-based electrodes. All the results indicated that electrodes based on modified MONs provide better surface area, surface coverage, charge transfer coefficients and rate constants as compared to those for simple MON-based electrodes. It is concluded that modification of simple MONs with BTC provided smaller particles size, better structural morphology and redox reactions assistance, making them suitable for better electrochemical applications. [ABSTRACT FROM AUTHOR]

Interfacial solar steam generation is a potential technology to relieve the freshwater shortage. However, developing a cost-effective method to design photo-absorbers with steady desalination performance remains a significant challenge. In this study, we designed, the Polyvinyl Alcohol (PVA): Glutaraldehyde (GA)/silver and gold plasmonic nanoparticle/activated carbon hydrogel nanocomposite as sponge-like photo-absorber materials. Glutaraldehyde (GA) as a simple chemical crosslinking added to PVA/AC hydrogel along with to Au or Ag nanoparticles for increasing the light absorption. The optical properties results show that by adding gold and silver nanoparticles as plasmonic agent in this hydrogel, the light absorption is increased in wet hydrogel which can reach 74% with water evaporate rate of 5.58 kg−2 m−2 h−1. The PVA: GA: Au hydrogel (AC) nanocomposite shows a steady evaporation rate of about 5.08 kg−2 m−2 h−1 under 0.1 solar intensity during desalination. The 24 h of indoor desalination experiments proves that both hydrogel is durable and has a steady evaporation performance. The PVA:GA: Au hydrogel (AC) nanocomposite and PVA:GA: Ag hydrogel (AC) nanocomposite hydrogels were characterized by XRD analysis, FE-SEM imaging, UV–Vis and FTIR spectroscopy. The XRD results for PVA:GA: Au hydrogel (AC) nanocomposite and PVA:GA: Ag hydrogel (AC) nanocomposite showed that the amorphous pattern decreased sharply due to a decrease in the PVA peak. Also, the both peaks of Au and Ag with the tetragonal and cubic structures were observed with the preferred direction (110). FE-SEM images of PVA:GA: Au hydrogel (AC) nanocomposite and PVA:GA: Ag hydrogel (AC) nanocomposite showed micro pores on the surface of hydrogels and porous structure of the hydrogel network is formed. Also, the results of FTIR spectroscopy showed that with increasing metal nanoparticles, there is no difference in the type of a factor group and only affects the intensity of the peaks and leads to a little shift of the peaks to the modes of pure PVA. The PVA:GA: Au (Ag) hydrogel (AC) nanocomposite offers a substantial possibility in mitigating freshwater shortages. [ABSTRACT FROM AUTHOR]

In recent years, metal nanoparticles (MNPs) have gained significant research interest owing to their versatile characteristics in diversified applications ranging from catalysis to biomedical sciences. Due to their notable and improved properties such as higher flexibility, facile processability, thermal stability, mechanical strength, and exceptional optoelectrical and magnetic behavior as compared to pristine metal nanoparticles, the polymer mediated nanoparticles have recently drawn interest from both industry and academia. In this novel investigation, we report a sustainable synthesis of Ag, Fe, Cu, and Zn metal nanoparticles using a chemical reduction method using polyamide (PA) and polyhydrazide (PH) matrices. This work is innovative in that it makes use of these polymer matrices for improved MNP synthesis, offering a unique combination of thermal and structural features. The polymers-supported metal nanoparticles were characterized for structural, thermal, optical, chemical, and morphological characteristics using XRD, TGA, UV-Vis, IR spectroscopy, and SEM analysis, respectively. XRD measurements demonstrated a significant rise in the crystallinity index for the produced metal nanoparticles, indicating a significant increase in crystallinity quantitatively. The effective synthesis of nanoparticles with precise attributes was confirmed by UV-Vis spectroscopy, which showed a significant absorption peak in the UV region. The thermogravimetric study suggested an improvement in thermal stability of around 25%. This work offers a flexible and eco-friendly method for synthesizing metal nanoparticles, demonstrating the usefulness of polyamide and polyhydrazide matrices as platforms for the synthesis of nanomaterials for numerous applications including catalysis, electronics, sensors, and biomedical applications. Highlights: A facile synthesis of metal nanoparticles (Ag, Fe, Cu, and Zn) via chemical reduction approach. The nanoparticles of Ag, Fe, Cu, and Zn are formed utilizing polyamide (PA) and polyhydrazide (PH) matrices. The synthesized metal nanoparticles exhibited higher crystallinity, better thermal stability, high absorption in UV range. This work offers a potential for numerous applications including catalysis, electronics, sensors, and biomedical applications. [ABSTRACT FROM AUTHOR]

Nanoparticle synthesis under environmentally friendly conditions has been conducted utilizing natural resources in order to reduce the reliance on hazardous chemicals. For example, the utilization of microbial synthesis has enabled the production of nanoparticles that exhibit biocompatibility, stability, and safety. Microorganisms facilitate the growth of crystals while preventing aggregation. They serve as both reducing agents and capping agents by offering enzymes, peptides, poly(amino acids), polyhydroxyalkanoate, and polysaccharides. In this review, we present an overview of nanoparticle synthesis based on microorganisms including bacteria, fungi, algae, and actinobacteria, encompassing metals such as gold (Au), silver (Ag), platinum (Pt), palladium (Pd), copper (Cu), titanium dioxide ((TiO2), zinc oxide (ZnO), iron oxide (Fe2O3), and selenium (Se). The nanoparticles typically vary in size from 1 to 100 nm and exhibit various shapes including spherical, rod-shaped, triangular, cubic, and hexagonal shapes. Additionally, this review discusses the mechanisms behind the synthesis of metal nanoparticles by microorganisms, whether they occur intracellularly or extracellularly. [ABSTRACT FROM AUTHOR]

The biosynthesis of novel nanoparticles with varied morphologies, which has good implications for their biological capabilities, has attracted increasing attention in the field of nanotechnology. Bioactive compounds present in the extract of fungi, bacteria, plants and algae are responsible for nanoparticle synthesis. In comparison to other biological resources, brown seaweeds can also be useful to convert metal ions to metal nanoparticles because of the presence of richer bioactive chemicals. Carbohydrates, proteins, polysaccharides, vitamins, enzymes, pigments, and secondary metabolites in brown seaweeds act as natural reducing, capping, and stabilizing agents in the nanoparticle's synthesis. There are around 2000 species of seaweed that dominate marine resources, but only a few have been reported for nanoparticle synthesis. The presence of bioactive chemicals in the biosynthesized metal nanoparticles confers biological activity. The biosynthesized metal and non-metal nanoparticles from brown seaweeds possess different biological activities because of their different physiochemical properties. Compared with terrestrial resources, marine resources are not much explored for nanoparticle synthesis. To confirm their morphology, characterization methods are used, such as absorption spectrophotometer, X-ray diffraction, Fourier transforms infrared spectroscopy, scanning electron microscope, and transmission electron microscopy. This review attempts to include the vital role of brown seaweed in the synthesis of metal and non-metal nanoparticles, as well as the method of synthesis and biological applications such as anticancer, antibacterial, antioxidant, anti-diabetic, and other functions. [ABSTRACT FROM AUTHOR]

Understanding the fluorescence resonance energy transfer (FRET) of metal nanoparticles at the atomic level has long been a challenge due to the lack of accurate systems with definite distance and orientation of molecules. Here we present the realization of achieving FRET between two atomically precise copper nanoclusters through cocrystallization-induced spatial confinement. In this study, we demonstrate the establishment of FRET in a cocrystallized Cu8(p-MBT)8(PPh3)4@Cu10(p-MBT)10(PPh3)4 system by exploiting the overlapping spectra between the excitation of the Cu10(p-MBT)10(PPh3)4 cluster and the emission of the Cu8(p-MBT)8(PPh3)4 cluster, combined with accurate control over the confined space between the two nanoclusters. Density functional theory is employed to provide deeper insights into the role of the distance and dipole orientations of molecules to illustrate the FRET procedure between two cluster molecules at the electronic structure level. Understanding FRET of metal nanoparticles at the atomic level has long been a challenge. Here, the authors have achieved FRET activity with atomically precise Cu clusters by using a cocrystallisation-induced spatial confinement strategy. [ABSTRACT FROM AUTHOR]

Green synthesis is a reliable way to synthesize metal oxide nanoparticles (NPs) without affecting the environment. Plant extracts act as reducing agents that favor the synthesis of NPs. In this study, jackfruit aqueous extract was used as a fuel in the solution combustion synthesis of lanthanum oxide (La2O3) NPs. X-ray diffraction (XRD) confirmed the formation of the hexagonal structure of La2O3 NPs. The scanning electron microscope (SEM) and energy dispersive X-ray (EDS) spectrum confirm the needle-shaped morphology and purity of the La2O3 NPs, respectively. Furthermore, La2O3 was utilized as a photocatalyst for the photodegradation of methylene blue dye under visible light radiation, demonstrating high efficiency within 90 min of light irradiation. The electrochemical characteristics of La2O3 were studied using a carbon paste electrode in a 0.1 M HCl solution. These La2O3 samples exhibited superior sensitivity in cyclic voltammetry tests towards the detection of ascorbic acid and lead nitrate. Consequently, La2O3 holds potential for applications in electrochemical sensor technology. [ABSTRACT FROM AUTHOR]

Printed circuit boards, which make up part of waste from electrical and electronic equipment, contain elements that can be economically reused, such as copper, silver, gold, and nickel, as well as metals that are harmful to the environment and health, such as lead, mercury, and cadmium. Thus, through recycling this scrap, materials that would otherwise be discarded can be reinserted as secondary raw materials to produce new consumer goods through urban mining. In this context, the synthesis of nanoparticles shows promise as it allows the reinsertion of these materials in the manufacture of new products. Therefore, this study used obsolete computer motherboards as a secondary material to obtain copper to produce nanoparticles of this metal. From a solution based on the leach liquor of this scrap, a purification route using solvent extraction was defined and applied to the real leach liquor. Applying the hydroxyoxime extractant at a dilution of 20% (v/v) in kerosene, A/O of 1/1, 298 K, and 0.25 h of contact during extraction, and stripping in H2SO4 (2 M), 298 K, 0.25 h, W/O ratio of 3/1, and two theoretical countercurrent stages, a solution containing more than 95% of the copper in the leach liquor could be obtained with less than 1% of contaminants. From this purified liquor, nanoparticles containing copper and metallic copper oxides and hydroxides were produced, with an average size of 84 nm, at pH 11, 3 h of hot stirring, volume of 0.015 L of ascorbic acid (0.50 M) and 0.015 L of precursor solution (0.03 M Cu), and temperature (343 K). [ABSTRACT FROM AUTHOR]

The binding efficiency of graphene oxide and selected transition metal sulfide nanoparticles (Co3S4, NiS, CuS, and ZnS) observed by fluorescence spectroscopy, and corresponding changes observed in the hydrodynamic size by DLS are related to each other. We observed that changes in the size of nanoparticles before and after binding have a similar pattern to the estimated binding constants, which shows a relationship between fluorescence spectroscopy and dynamic light scattering. This relation is yet unknown in the literature to the best of our understanding. Further, the binding mechanism is dependent on the nature of nanoparticles, where ZnS nanoparticles have highest binding towards graphene oxide, followed by CuS, Co3S4, and NiS nanoparticles respectively. The electronic interaction of the aromatic double bonds of GO with the nanoparticles is revealed along with both static and dynamic binding mechanisms. The stability of nanocomposites is also investigated for these titration experiments of nanoparticles and graphene oxide. [ABSTRACT FROM AUTHOR]

Recently, metal nanoparticles synthesized by bio-fabrication methods were being used for various life-saving treatments. In our present study, AuNPs were fabricated using aqueous Panicum Maximum (P. Maximum) leaf extract. The analysis of UV–Visible spectrophotometer indicated the excitation of the formed AuNPs, specifically, a distinct SPR band positioned nearly at 530 nm. The formation of AuNPs with 45–50-nm size range was confirmed by TEM. Also, SAED pattern was utilized to characterize single crystalline nature of the biofabricated AuNPs. Further, the anticancer effects of synthesized AuNPs were studied against HepG2 cells. After incubating HepG2 cells with AuNPs, the amount of cytochrome c, CASP 9/CASP 8/CASP 3/BAX expression level, formation of ROS, and cell viability were analyzed. Outcomes of our study showed a dose determined cytotoxicity and half inhibitory concentration (IC50) of 75 μg/mL for the synthesized AuNPs. Cytotoxicity of AuNPs was accompanied by cell apoptosis and ROS induction in cell line of HepG2. Based on our results, AuNPs could have potential for development of new drugs for therapy of liver hepatocellular carcinoma in nursing care. [ABSTRACT FROM AUTHOR]

Two-step electrosynthesis of nanocomposites of bimetallic PdCu and PdAu nanoparticles (NPs) with iron(II), aluminum(III), zinc(II), copper(I), and titanium(IV) oxide−hydroxides was carried out in the presence of stabilizer cetyltrimethylammonium chloride (CTAC). In the first step, efficient syntheses of Fe, Al, Zn, Cu, and Ti oxide−hydroxides were carried out by reducing dissolved oxygen or methylviologen and generating metal ions by dissolution the corresponding metal anodes. In the second step, syntheses of bimetallic PdCu and PdAu NPs were proceeded by methylviologen (MV2+)-mediated electroreduction of equimolar concentration of Cu(II), Pd(II), and Au(I) in the presence of CTAC and obtained oxide−hydroxides. The results of the syntheses were nanocomposites of mainly spherical MNPs stabilized with CTAC on the surface of oxide−hydroxides with an average size of 2 to 10 nm, but the PdAu@CTAC/Cu2O nanocomposite showed formation of two NPs types with sizes 7 ± 2 nm (Pd) and 24 ± 10 nm (Au). X-ray powder diffraction data showed the absence of metal crystallites in almost all samples with PdCu due to the amorphous phase, and the presence of bimetallic crystallites with sizes ranging from 1 to 15 nm in PdAu composites. In the test reaction of p-nitrophenol reduction all the tested nanocomposites exhibited catalytic activity. [ABSTRACT FROM AUTHOR]

Gold nanoclusters are a smart platform for sensing potassium ions (K+). They have been synthesized using bovine serum albumin (BSA) and valinomycin (Val) to protect and cap the nanoclusters. The nanoclusters (Val-AuNCs) produced have a red emission at 616 nm under excitation with 470 nm. In the presence of K+, the valinomycin polar groups switch to the molecule's interior by complexing with K+, forming a bracelet structure, and being surrounded by the hydrophobic exterior conformation. This structure allows a proposed fluorometric method for detecting K+ by switching between the Val-AuNCs' hydrophilicity and hydrophobicity, which induces the aggregation of gold nanoclusters. As a result, significant quenching is seen in fluorescence after adding K+. The quenching in fluorescence in the presence of K+ is attributed to the aggregation mechanism. This sensing technique provides a highly precise and selective sensing method for K+ in the range 0.78 to 8 µM with LOD equal to 233 nM. The selectivity of Val-AuNCs toward K+ ions was investigated compared to other ions. Furthermore, the Val-AuNCs have novel possibilities as favorable sensor candidates for various imaging applications. Our detection technique was validated by determining K+ ions in postmortem vitreous humor samples, which yielded promising results. [ABSTRACT FROM AUTHOR]

The bismuth-layered ferroelectric (BLF) oxides are promising photocatalysts due to their wide band gap, photo-coupled ferro properties, Pb-Free composition, and excellent chemical stability. In this study, polycrystalline SrBi 4 Ti 4 O 15 (SBT) is used as the target photocatalyst, and its photocatalytic performance was evaluated in terms of Rhodamine-B dye degradation under UV light. Moreover, the influence of metal deposition (Ag, Zn, Fe, and Bi) was also explored. The powders of SBT and its metal-decorated derivatives were synthesized and structural, compositional, and optical properties were studied in detail using XRD, XPS, EDS, FTIR, UV–Vis, Raman, and PL spectroscopy. The pristine SBT powders showed 19% photodegradation after 60 min of exposure to UV radiation. Metal nanoparticles deposited on the surface of the SBT were found to improve photocatalytic capacity and a nearly threefold increase (53%) in degradation rate was achieved for Bi-decorated SBT. The rate constant and the turnover frequency are 0.01336 min - 1 and 13.2 × 10 - 3 mol Rh - B mol metal h - 1 , respectively. The degradation was observed to follow a Langmuir–Hinshelwood (LH) model, indicating that the process is first order. [ABSTRACT FROM AUTHOR]

Top-down strategy has been widely applied for synthesis of metal single atom catalysts (SACs) via converting metal nanoparticles or bulk metals into atomically dispersed species. Here, we report a simple electrochemical atomic migration strategy for top-down synthesis of SACs via a facile cathodic corrosion process without involving high temperature or harsh atmosphere. Atoms of metal nanoparticles on cathode are firstly disbanded under high negative voltage, and emitted into the electrolyte in the form of atomic metal anions in Zintl phase. The escaped atomically dispersed metal species are then oxidized by water molecules and captured by the defects on the pre-added nitrogen doped carbon carriers in the electrolyte. This cathodic corrosion strategy is confirmed to be suitable for scalable synthesis of kinds of metal SACs (e.g., Pt, Pd, and Ir) on doped carbon materials. Typically, the as-prepared nitrogen doped carbon powder supported Pt SACs exhibit superior catalytic activity toward hydrogen evolution reaction (HER) with a low overpotential of 0.024 V at 10 mA·cm−2 and a low Tafel slope of 29.7 mV·dec−1 as well as a long-term durability. [ABSTRACT FROM AUTHOR]

For accurate patient identification and treatment, early-stage disease diagnosis is particularly important. However, a lack of patient compliance with the current diagnostic techniques prevents prompt diagnosis, making the creation of noninvasive diagnostic tools essential. Breath analysis, one of the most promising noninvasive diagnostic techniques that has also attracted a lot of research interest recently, finds gas analytes like exhaled volatile organic compounds (VOCs) and inorganic gases that are thought to be significant biomarkers for a variety of disease types. The common technique for the detection of biomarkers in breath involves spectrometric-based measurements. Despite their precision and accuracy to detect a low concentration of exhaled breath, these techniques have some disadvantages such as lack of portability, being expensive, high power demand, and requiring trained staff to operate them. Consequently, recent interest in nanotechnology has accelerated the development of new chemosensors, sensing techniques, and enhanced the performance and sensitivity of existing chemosensors in the rapidly evolving field of biosensing. Chemosensors made with nanotechnology can identify diseases and monitor treatment outcomes. This review paper aims to present a current overview of the major chemosensor categories investigated for applications in disease diagnosis via the detection of exhaled gas analytes and to emphasize the significance of nanomaterials. Various nanomaterial-based chemosensors, prepared with several metal and metal oxide nanoparticles for detections of different types of volatile organic compound biomarkers. [ABSTRACT FROM AUTHOR]

The use of bio-nanotechnology in agriculture—such as the biological applications of metal oxide nanoparticles (NPs)—greatly improves crop yield and quality under different abiotic stress factors including soil metal contamination. Here, we explore the effectiveness of zinc oxide (ZnO)-NPs (0, 50 mg/L) foliar spraying to ameliorate the detrimental effects of cadmium (Cd) on the water transport and nitrogen metabolism in tomato (Solanum lycopersicum Mill. cv. Chibli F1) plants grown on a Cd-supplied (CdCl2; 0, 10, 40 μM) Hoagland nutrient solution. The results depicted that the individually studied factors (ZnO-NPs and Cd) had a significant impact on all the physiological parameters analyzed. Independently to the Cd concentration, ZnO-NPs-sprayed plants showed significantly higher dry weight (DW) in both leaves and roots compared to the non-sprayed ones, which was in consonance with higher and lower levels of Zn2+ and Cd2+ ions, respectively, in these organs. Interestingly, ZnO-NPs spraying improved water status in all Cd-treated plants as evidenced by the increase in root hydraulic conductance (L0), apoplastic water pathway percentage, and leaf and root relative water content (RWC), compared to the non-sprayed plants. This improved water balance was associated with a significant accumulation of osmoprotectant osmolytes, such as proline and soluble sugars in the plant organs, reducing electrolyte leakage (EL), and osmotic potential (ψπ). Also, ZnO-NPs spraying significantly improved NO3− and NH4+ assimilation in the leaf and root tissues of all Cd-treated plants, leading to a reduction in NH4+ toxicity. Our findings point out new insights into how ZnO-NPs affect water transport and nitrogen metabolism in Cd-stressed plants and support their use to improve crop resilience against Cd-contaminated soils. [ABSTRACT FROM AUTHOR]

According to an estimate, 30% to 40%, of global fruit are wasted, leading to post harvest losses and contributing to economic losses ranging from $10 to $100 billion worldwide. Among, all fruits the discarded portion of oranges is around 20%. A novel and value addition approach to utilize the orange peels is in nanoscience. In the present study, a synthesis approach was conducted to prepare the metallic nanoparticles (copper and silver); by utilizing food waste (Citrus plant peels) as bioactive reductants. In addition, the Citrus sinensis extracts showed the reducing activity against metallic salts copper chloride and silver nitrate to form Cu-NPs (copper nanoparticles) and Ag-NPs (Silver nanoparticles). The in vitro potential of both types of prepared nanoparticles was examined against plant pathogenic bacteria Erwinia carotovora (Pectobacterium carotovorum) and pathogens effect on human health Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Moreover, the in vivo antagonistic potential of both types of prepared nanoparticles was examined by their interaction with against plant (potato slices). Furthermore, additional antipathogenic (antiviral and antifungal) properties were also examined. The statistical analysis was done to explain the level of significance and antipathogenic effectiveness among synthesized Ag-NPs and Cu-NPs. The surface morphology, elemental description and size of particles were analyzed by scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy and zeta sizer (in addition polydispersity index and zeta potential). The justification for the preparation of particles was done by UV–Vis Spectroscopy (excitation peaks at 339 nm for copper and 415 nm for silver) and crystalline nature was observed by X-ray diffraction. Hence, the prepared particles are quite effective against soft rot pathogens in plants and can also be used effectively in some other multifunctional applications such as bioactive sport wear, surgical gowns, bioactive bandages and wrist or knee compression bandages, etc. [ABSTRACT FROM AUTHOR]

Co-exposure soil studies of pollutants are necessary for an appropriate ecological risk assessment. Here, we examined the effects of two-component mixtures of metal oxide nanoparticles (ZnO NPs or goethite NPs) with the insecticide chlorpyrifos (CPF) under laboratory conditions in short-term artificial soil assays using Eisenia andrei earthworms. We characterized NPs and their mixtures by scanning electron microscopy, atomic force microscopy, dynamic light scattering and zeta potential, and evaluated effects on metal accumulation, oxidative stress enzymes, and neurotoxicity related biomarkers in single and combined toxicity assays. Exposure to ZnO NPs increased Zn levels compared to control in single and combined exposure (ZnO NPs + CPF) at 72 h and 7 days, respectively. In contrast, there was no indication of Fe increase in organisms exposed to goethite NPs. One of the most notable effects on oxidative stress biomarkers was produced by single exposure to goethite NPs, showing that the worms were more sensitive to goethite NPs than to ZnO NPs. Acetylcholinesterase and carboxylesterase activities indicated that ZnO NPs alone were not neurotoxic to earthworms, but similar degrees of inhibition were observed after single CPF and ZnO NPs + CPF exposure. Differences between single and combined exposure were found for catalase and superoxide dismutase (goethite NPs) and for glutathione S-transferase (ZnO NPs) activities, mostly at 72 h. These findings suggest a necessity to evaluate mixtures of NPs with co-existing contaminants in soil, and that the nature of metal oxide NPs and exposure time are relevant factors to be considered when assessing combined toxicity, as it may have an impact on ecotoxicological risk assessment. [ABSTRACT FROM AUTHOR]