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Heavy metal contamination of water sources has long been a silent yet potent threat, endangering environmental and human health. Conventional wastewater treatments are costly due to high infrastructure expenses, energy consumption, and chemical usage. These treatments lead to secondary environmental pollution, such as producing toxic sludge, greenhouse gaseous emissions, and residual pollutants discharges. Therefore, more sustainable and cost-effective wastewater treatment alternatives are needed to overcome these challenges. Microalgae biosorption and bioaccumulation can bioremediate wastewater by effectively removing heavy metals and other contaminants, such as nitrate and phosphate. By utilizing sunlight and CO 2 for growth, microalgae cultivation reduces the need for expensive chemicals and energy-intensive operations in wastewater treatment. Additionally, microalgae can potentially convert heavy metal ions from wastewater into metal nanoparticles, providing a dual benefit of bioremediation and resource recovery. The primary objectives of this review are to assess the effectiveness of microalgae in heavy metal bioremediation and nanoparticle synthesis while also identifying critical research gaps and future directions for optimizing this biotechnology. Heavy metal ions in wastewater can be used as a metal precursor, and metal nanoparticles can be synthesized from wastewater. A review methodology was carried out to assess the availability of literature for readers to identify the research trends and gaps. Mechanisms of microalgae for the biogenesis of metal nanoparticles, including activation, growth, and termination phases, were elucidated. Various chemical interactions between metal ions and functional groups of microalgae, including amine (-NH 2 ), carboxyl (-COOH), phosphate (-PO 4 ), and hydroxyl (-OH) groups were evaluated. Nonetheless, this review also identifies the current challenges and future research directions for optimizing microalgae biotechnology in heavy metal bioremediation and nanoparticle biogenesis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Silver nanoparticles (Ag-NPs) have a unique mode of action as antibacterial agents in addition to their anticancer and antioxidant properties. In this study, microbial nanotechnology is employed to synthesize Ag-NPs using the cell filtrate of Streptomyces enissocaesilis BS1. The synthesized Ag-NPs are confirmed by ultraviolet-visible (UV-Vis), Fourier transform infrared (FT-IR), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Also, the effects of different factors on Ag-NPs synthesis were evaluated to set the optimum synthesis conditions. Also, the antibacterial, antibiofilm, and anticancer activity of Ag-NPs was assessed. The X-ray diffraction (XRD) analysis confirmed the crystalline nature of the sample and validated that the crystal structure under consideration is a face-centered cubic (FCC) pattern. The TEM examination displayed the spherical particles of the Ag-NPs and their average size, which is 32.2 nm. Fourier transform infrared spectroscopy (FTIR) revealed significant changes in functionality after silver nanoparticle dispersion, which could be attributed to the potency of the cell filtrate of Streptomyces enissocaesilis BS1 to act as both a reducing agent and a capping agent. The bioactivity tests showed that our synthesized Ag-NPs exhibited remarkable antibacterial activity against different pathogenic strains. Also, when the preformed biofilms of Pseudomonas aeruginosa ATCC 9027, Salmonella typhi ATCC 12023, Escherichia coli ATCC 8739, and Staphylococcus aureus ATCC 6598 were exposed to Ag NPs 50 mg/ml for 24 hours, the biofilm biomass was reduced by 10.7, 34.6, 34.75, and 39.08%, respectively. Furthermore, the Ag-NPs showed in vitro cancer-specific sensitivity against human breast cancer MCF-7 cell lines and colon cancer cell line Caco-2, and the IC 50 was 0.160 mg/mL and 0.156 mg/mL, respectively. The results of this study prove the ease and efficiency of the synthesis of Ag-NPs using actinomycetes and demonstrate the significant potential of these Ag-NPs as anticancer and antibacterial agents., (© 2024. The Author(s).)

Nanoparticles, especially silver nanoparticles (Ag NPs), have gained significant attention in recent years as potential alternatives to traditional antibiotics for treating infectious diseases due to their ability to inhibit the growth of microorganisms effectively. Ag NPs can be synthesized using fungi extract, but the method is not practical for large-scale production due to time and biomass limitations. In this study, we explore the use of chitosan to encapsulate the mycelia of the white-rot fungus Stereum hirsutum and form chitosan fungal beads for use in multiple extractions and nanoparticle synthesis. The resulting nanoparticles were characterized using various techniques, including UV-vis spectrophotometry, transmission electron microscopy, dynamic light scattering, and X-ray diffraction analysis. The analysis revealed that the synthesized nanoparticles were composed of chitosan-silver nanoparticles (CS-Ag NPs) with a size of 25 nm. The chitosan fungal beads were reused in three extractions and nanoparticle synthesis before they lost their ability to produce CS-Ag NPs. The CS-Ag NPs showed potent antimicrobial activity against phytopathogenic and human pathogenic microorganisms, including Pseudomonas syringae , Escherichia coli , Staphylococcus aureus , and Candida albicans , with minimum inhibitory concentrations of 1.5, 1.6, 3.1, and 4 µg/mL, respectively. The antimicrobial activity of CS-Ag NPs was from 2- to 40-fold higher than Ag NPs synthesized using an aqueous extract of unencapsulated fungal biomass. The CS-Ag NPs were most effective at a pH of five regarding the antimicrobial activity. These results suggest that the chitosan fungal beads may be a promising alternative for the sustainable and cost-effective synthesis of CS-Ag NPs with improved antimicrobial activity.

Implant-associated infection due to biofilm formation is a growing problem. Given that silver nanoparticles (Ag-NPs) have shown antibacterial effects, our goal is to study their effect against multispecies biofilm involved in the development of peri-implantitis. To this purpose, Ag-NPs were synthesized by laser ablation in de-ionized water using two different lasers, leading to the production of colloidal suspensions. Subsequently, part of each suspension was subjected to irradiation one and three times with the same laser source with which it was obtained. Ag-NPs were immobilized on the surface of titanium discs and the resultant materials were compared with unmodified titanium coupons. Nanoparticles were physico-chemically analysed to determine their shape, crystallinity, chemical composition, and mean diameter. The materials were incubated for 90 min or 48 h, to evaluate bacterial adhesion or biofilm formation respectively with Staphylococcus aureus or oral mixed bacterial flora composed of Streptococcus oralis , Actinomyces naeslundii , Veionella dispar , and Porphyromonas gingivalis . Ag-NPs help prevent the formation of biofilms both by S. aureus and by mixed oral bacterial flora. Nanoparticles re-irradiated three times showed the biggest antimicrobial effects. Modifying dental implants in this way could prevent the development of peri-implantitis.

Metal surfaces with intrinsic chirality play an irreplaceable role in many significant enantioselective chemical processes such as enantioselective catalysis, sensing, and separation. Nonetheless, current methods for the precise preparation of such chiral surfaces suffer with issues of unscalable production and low surface areas. Herein, we report the synthesis of chiral Au nanoparticles with precisely determined homochiral facets. Though a scalable wet chemical method, {125̅8} R and {85̅12} S high-Miller-index facets are obtained with the l- and d-chiral Au nanocrystals, respectively. The growth process of these homochiral facets is investigated, and a new nanocrystal growth pathway is revealed. More importantly, the remarkable enantioselective recognition properties of these homochiral surfaces are demonstrated and enable an efficient electrochemical method for chiral discrimination of l-/d-tryptophan. These results provide a foundation of fundamental studies of heterogeneous enantioselective processes and may pave way for the development of nanocatalysts for enantioselective chemistry.

Controlling the formation of nanosized branched nanoparticles with high uniformity is one of the major challenges in synthesizing nanocatalysts with improved activity and stability. Using a cubic-core hexagonal-branch mechanism to form highly monodisperse branched nanoparticles, we vary the length of the nickel branches. Lengthening the nickel branches, with their high coverage of active facets, is shown to improve activity for electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF), as an example for biomass conversion., (© 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.)

This article demonstrates a new kind of a highly sensitive lateral flow immunoassay (LFIA). It is based on the enlargement of the size of gold nanoparticles (GNPs) directly on the test strip after a conventional LFIA. Particle size enlargement is accomplished through the catalytic reduction of HAuCl 4 in the presence of H 2 O 2 and through the accumulation of additional gold on the surface of the GNPs. To attain maximal enhancement of the coloration of the zone in the test strip and to achieve a minimal background, the concentration of precursors, the pH value, and the incubation time were optimized. GNPs on the test strip are enlarged from 20 to 350 nm after a 1-min treatment at room temperature. The economically important and widespread phytopathogen potato virus X (PVX) was used as the target analyte. The use of the GNP enlargement method results in a 240-fold reduction in the limit of the detection of PVX, which can be as low as 17 pg·mL -1 . The total duration of the assay, including virus extraction from the potato leaves, lateral flow, and the enhancement process, is only 12 min. The diagnostic efficiency of the technique was confirmed by its application to the analysis of potato leave samples. No false positives or false negatives were found. The technique does not depend on specific features of the target analyte, and it is conceivably applicable to numerous GNP-based LFIAs for important analytes. Graphical abstract An enlargement solution (containing HAuCl 4 and H 2 O 2 ) was dripped on the strip after common lateral flow immunoassay. Gold nanoparticles on the strip (20 nm) catalyze gold reduction and the formation of larger particles (up to 350 nm), resulting in a 240-fold lower detection limit within 1 min.

The objectives of this study were the biosynthesis of silver nanoparticles (NPs) by biotransformations using Saccharomyces cerevisiae and analysis of the sizes and shapes of the NPs produced. Dried and freshly cultured S. cerevisiae were used as the biocatalyst. Dried yeast synthesized few NPs, but freshly cultured yeast produced a large amount of them. Silver NPs were spherical, 2-20 nm in diameter, and the NPs with the size of 5.4 nm were the most frequent ones. NPs were seen inside the cells, within the cell membrane, attached to the cell membrane during the exocytosis, and outside of the cells.

The objectives were to study the potential of Althaea officinalis radix in production of silver NPs, and the effect of the extract ethanol concentration on the produced NPs. Seventy and ninety-six percent hydroalcoholic extracts were prepared by percolation of the plant powder. The extract was concentrated by rotary evaporator and then freeze-dried. Silver ions were determined using atomic absorption analysis. The NPs were characterized by Nano-Zeta Sizer and TEM. Both of 70% and 96% of hydroalcoholic extracts of A. officinalis radix successfully synthesized spherical and poly-dispersed silver NPs. The conversion was fast and almost completed in 5 h.

The objectives were to study the potential of Pulicaria gnaphalodes (Vent.) Boiss. aerial parts in production of nanoparticles and the effect of the extraction solvent on the produced nanoparticles. Methanol and dichloromethane extracts were prepared by percolation of the plant powder. Both the extracts of P. gnaphalodes (Vent.) Boiss. successfully produced small and polydispersed nanoparticles with low aggregates in early hours of the biotransformation. Methanol extract produced spherical and many single nanoparticles, whereas dichloromethane produced porous polyhedral and more aggregated nanoparticles. Methanol extract of this plant seems to be quiet useful for industrial scale production of nanoparticles.

Silver nanoparticles (AgNPs) were robustly synthesized from aqueous AgNO3 with alkali lignin (low sulfonate) (ALls) severing as dual reducing and capping agent. The AgNP synthesis mechanisms were highly pH dependent. Under neutral and acidic conditions, polydispersed AgNPs were synthesized via the self-catalyzed reduction of Ag(+) on instantaneously formed Ag2O surfaces followed by the slower pseudo-first order reduction. The Ag2O nanoparticles functioned as the nucleating sites for the reduction of remaining silver cations to form AgNPs whose size and size distribution strongly dependent of lignin concentrations. AgNPs were optimally synthesized by reducing 2 mmol/L AgNO3 with 0.16 wt% ALls at pH 10 and 85°C in 30 min to near 100% yield in bimodal distributed sizes with 23% and 77% in feret diameters of 7.3 (± 2.2)nm and 14.3 (± 1.8)nm, respectively., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Between their many applications bismuth nanoparticles (BiNPs) are showing interest as pre-concentrators in heavy metals detection while being applied as working electrode modifiers used in electrochemical stripping analysis. From the different reported methods to synthesize BiNPs we are focused on the typical polyol method, largely used in these types of metallic and semi-metallic nanoparticles. This study presents the strategy for an easy control of the shape and size of BiNPs including nanocubes, nanosferes and triangular nanostructures. To improve the BiNP size and shape, different reducing agents (ethylene glycol or sodium hypophosphite) and stabilizers (polyvinyl pyrrolidone, PVP, in different amounts) have been studied. The efficiency of BiNPs for heavy metals analysis in terms of detection sensitivity while being used as modifiers of screen-printed carbon electrodes including the applicability of the developed device in real sea water samples is shown. A parallel study between the obtained nanoparticles and their performance in heavy metal sensing has been described in this communication., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Context: There is an ever-growing need to develop green, non-toxic, and eco-friendly procedures for synthesis and assembly of nanoparticles (NPs) with the desired morphologies and sizes. The hydroalcoholic extract of Persian oak leaves [Quercus brantii Lindl. (Fagaceae)] contains high content of phenolic and flavonoid compounds with strong antioxidant activities, and it seems that this plant can be considered a good candidate for metal nanoparticle synthesis., Objective: The potential of Q. brantii leaves in the production of silver NPs and the effect of the extract ethanol concentration on the produced NPs were studied., Materials and Methods: Quercus brantii leaves were freshly collected, air-dried at room temperature, powdered, and sieved. Hydroalcoholic extracts (70% and 96%) were prepared by percolation of the plant powder. The reaction mixtures contained (final concentrations): AgNO3 (1 mM) as the substrate, plant extract as the biocatalyst, and phosphate buffer (pH = 7, 100 mM) as the reaction medium. Silver ions were determined using atomic absorption analysis. Particle size distribution of NPs was analyzed using Nano-Zeta Sizer (Malvern Instruments Ltd, Malvern, UK). Samples for TEM were prepared by drop-coating the silver nanoparticle suspensions onto carbon-coated copper grids., Results: Hydroalcoholic extract (96%) of Q. brantii successfully produced quite small (as small as 0.83 nm and the mean size of 6 nm), spherical, and poly-dispersed NPs with low aggregates. The conversion was fast and completed in 5 h., Discussion and Conclusion: This plant and the extraction method seem to be quiet attractive for industrial scale production of NPs.

The shapes of noble metal nanoparticles directly impact their properties and applications, including in catalysis and plasmonics, and it is therefore important to understand how multiple distinct morphologies can be controllably synthesized. Solution routes offer powerful capabilities for shape-controlled nanoparticle synthesis, but the earliest stages of the reaction are difficult to interrogate experimentally and much remains unknown about how metal nanoparticle morphologies emerge and evolve. Here, we use a well-established polyol process to synthesize uniform rhodium nanoparticle cubes, icosahedra, and triangular plates using bromide, trifluoroacetate, and chloride ligands, respectively. In all of these systems, we identified rhodium clusters with diameters of 1-2 nm that form early in the reactions. The colloidally stable metal cluster intermediates served as a stock solution of embryonic species that could be transformed predictably into each type of nanoparticle morphology. The anionic ligands that were added to the embryonic species determined their eventual fate, e.g., the morphologies into which they would ultimately evolve. Extensive high-resolution transmission electron microscopy experiments revealed that the growth pathway-monomer addition, coalescence, or a combination of the two-was different for each of the morphologies, and was likely controlled by the interactions of each specific anionic adsorbate with the embryonic species. Similar phenomena were observed for related palladium and platinum nanoparticle systems. These studies provide important insights into how noble metal nanoparticles nucleate, the pathways by which they grow into several distinct morphologies, and the imperative role of the anonic ligand in controlling which route predominates in a particular system.

We introduce an approach to synthesize rare earth oxide nanoparticles using high temperature without aggregation of the nanoparticles. The dispersity of the nanoparticles is controlled at the nanoscale by using small organosilane molds as reaction containers. Zeptoliter reaction vessels prepared from organosilane self-assembled monolayers (SAMs) were used for the surface-directed synthesis of rare earth oxide (REO) nanoparticles. Nanopores of octadecyltrichlorosilane were prepared on Si(111) using particle lithography with immersion steps. The nanopores were filled with a precursor solution of erbium and yttrium salts to confine the crystallization step to occur within individual zeptoliter-sized organosilane reaction vessels. Areas between the nanopores were separated by a matrix film of octadecyltrichlorosilane. With heating, the organosilane template was removed by calcination to generate a surface array of erbium-doped yttria nanoparticles. Nanoparticles synthesized by the surface-directed approach retain the periodic arrangement of the nanopores formed from mesoparticle masks. While bulk rare earth oxides can be readily prepared by solid state methods at high temperature (>900 °C), approaches for preparing REO nanoparticles are limited. Conventional wet chemistry methods are limited to low temperatures according to the boiling points of the solvents used for synthesis. To achieve crystallinity of REO nanoparticles requires steps for high-temperature processing of samples, which can cause self-aggregation and dispersity in sample diameters. The facile steps for particle lithography address the problems of aggregation and the requirement for high-temperature synthesis.

AbstractThe green synthesis of metal nanoparticles (NPs) using plant extract is particularly irresistible technique. This study utilizes hydroalcoholic Endocomia macrocoma leaf extract to fabricate bismuth NPs (BiNPs). The synthesized BiNPs were characterized by UV–visible spectroscopy to assess its optical activities, FTIR analysis identified the functional groups in plant extract, and the synthesis of BiNPs. X-ray diffraction (XRD) gives the crystalline nature of the NPs. Dynamic light scattering (DLS) of the NPs shows an average size of 99.1 nm and 21.34 mV zeta potential of the NPs. Scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS) confirms the size and composition of the synthesized NPs, spherical shape of the NPs with size ranges 30–60 nm confirmed by transmission electron microscope (TEM). BiNPs were assessed the thermal stability by thermogravimetric (TG) analysis and differential scanning calorimetry (DSC) analysis for temperature and endothermic or exothermic processes, respectively. BiNPs showed good antibacterial activity against E. coli, P. aeruginosa, B. subtilis, and B. cereus with minimum inhibitory concentration (MIC) value of 250 µg/mL. Also, they exhibited antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) with IC50 values of 125 µg/mL. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that BiNPs have effective potential anticancer properties against human pancreatic (PANC2) and esophagus (KYSE-30) cancer cell lines with IC50 values of 48.31 and 66.94 µg/mL, respectively. Anti-reactive oxygen species (Anti-ROS) analysis clearly shows 89% cell viability of the NPs. Consequently, our results imply that BiNPs derived from E. macrocoma may be better natural therapy than chemical-based sources for medicinal purposes. [ABSTRACT FROM AUTHOR]

Controlling the size and composition of metal nanoparticles is of considerable interest, as these are essential to their catalytic properties. Recently, our group has developed a preorganization strategy for controlled Ir nanoparticle synthesis inside Pt12L24 nanospheres. In the current contribution, we expand this method to the controlled synthesis of Rh nanoparticles. The encapsulated RhI complexes (Rh‐s @ G‐sphere) led to reasonable size control (2.8 ± 0.9 nm). Next, we demonstrated the formation of Rh‐Ir alloyed nanoparticles with varying Rh/Ir compositions, by preorganization of the respective metal complexes inside Pt12L24 nanospheres based on complementary hydrogen bonds before the reduction step that leads to nanoparticle formation. These heterometallic particles were evaluated in the hydrogenation of cinnamaldehyde (7) as a probe reaction. Besides a high activity in this probe reaction, the Rh particles also catalyzed the conversion of the solvent (CH3CN). The formed basic amine leads to follow‐up reactions of the product and compatibility issues with the hosting nanosphere. The solvent hydrogenation was effectively suppressed by using the Rh:Ir alloyed nanoparticles, provided that they contain > 66% Ir. Compared to the monometallic Ir particles (Ir‐s @ G‐sphere), the Rh:Ir alloyed nanoparticles displayed higher catalytic activity, reaching optimal selectivity and activity at an 8:16–Rh:Ir ratio. The combined catalytic results illustrate that preorganization of the metal complexes in the nanosphere before the reduction with hydrogen effectively facilitates the formation of Rh:Ir alloyed nanoparticles, which allows for tuning a catalyst to create a more active and selective catalyst compared to monometallic or nonencapsulated Rh/Ir particles. [ABSTRACT FROM AUTHOR]

This study presents the synthesis of metal nanoparticles (NPs) with antimicrobial properties from cyanobacterial biomass. Silver (AgNP), copper (CuNP), and zinc (ZnNP) nanoparticles were prepared from exopolysaccharides (EPSs) obtained from isolated cyanobacterial strains. The antimicrobial activity of AgNPs against Escherichia coli and Staphylococcus aureus was evaluated, and compared with CuNPs and ZnNPs, AgNPs were found to have a greater capacity to inhibit bacterial growth. The main factors influencing antimicrobial activity are the concentration and type of metal used. Using an optimized experimental design, specific conditions were established to maximize the antimicrobial efficacy of the synthesized NPs. The characterization of the nanoparticles included UV–VIS, FTIR, and EDX techniques, which confirmed the formation and purity of the AgNPs. This study highlights the effectiveness of cyanobacterial EPS as a reducing and stabilizing agent and provides a sustainable and efficient alternative for producing nanoparticles with biomedical applications. [ABSTRACT FROM AUTHOR]

Green nanotechnology comprises the use of natural sources such as plant extracts as both reducing and stabilizing agents thereby reducing the reliance on hazardous chemicals. Recent breakthroughs in nanotechnology involve the incorporation of various metals to create mono and bimetallic nanoparticles, catalyzing transformative shifts. However, concerns arise due to the environmental impact of traditional synthesis methods. An alternative approach focuses on biosynthesized metal nanoparticles using clay, specifically Bentonite, MMT (Montmorillonite) and Kaolinite as supportive materials, emphasizing the prevention of agglomeration with clay and the use of plant extracts. The integration of clay, especially Bentonite, MMT and Kaolinite enhances the stability and functionality. The review emphasizes mitigating environmental impact by reducing metal ions and explores the use of phytochemicals fro environmentally friendly nanoparticle synthesis. Incorporating clay minerals not only improves synthesis efficiency but also minimizes the ecological footprint. Future research is expected to focus on integrative approaches in plant nanotechnology, particularly in agriculture and broader plant science. The comprehensive review covers literature from 2015 to 2023, providing systematic and interpretative data, highlighting progress and potential in eco-friendly metal nanoparticles synthesis supported on clay minerals. [ABSTRACT FROM AUTHOR]

Metallic nanoparticles have found wide applications due to their unique physical and chemical properties. Green biosynthesis using plants, microbes, and plant/microbial extracts provides an environmentally friendly approach for nanoparticle synthesis. This review discusses the mechanisms and factors governing the biosynthesis of metallic nanoparticles such as silver, gold, and zinc using various plant extracts and microorganisms, including bacteria, fungi, and algae. The phytochemicals and biomolecules responsible for reducing metal ions and stabilizing nanoparticles are discussed. Key process parameters like pH, temperature, and precursor concentration affecting particle size are highlighted. Characterization techniques for confirming the formation and properties of nanoparticles are also mentioned. Applications of biosynthesized nanoparticles in areas such as antibacterial delivery, cancer therapy, biosensors, and environmental remediation are reviewed. Challenges in scaling up production and regulating nanoparticle properties are addressed. Power Point 365 was used for creating graphics. Overall, green biosynthesis is an emerging field with opportunities for developing eco-friendly nanomanufacturing platforms using abundant natural resources. Further work on optimizing conditions, standardizing protocols, and exploring new biosources is needed to realize the full potential of this approach. [ABSTRACT FROM AUTHOR]

Until now, the therapeutic potential of metal nanoparticles (NPs) has received much attention thanks to their unique properties. In addition, natural extracts of plants have shown significant therapeutic ability in various diseases. Therefore, the present study aimed to synthesize AuNPs using aqueous extracts of Hedra helix (Hh-AuNPs), Senna alexandrina (Sa-AuNPs), Thyme vulgaris (Tv-AuNPs) and Tribulus terrestris (Tt-AuNPs) and then investigate their antioxidant and cytotoxic effects on cancerous and normal breast cell lines. For this purpose, the prepared Phyto-NPs were analyzed employing the TEM technique and UV–Vis spectroscopy. The antioxidant activities of all aqueous extracts and the Phyto-NPs were analyzed by FRAP and DPPH assays. Their cytotoxic effects against the MCF-7, MCF-10 and MDA-MB-231 cell lines were also determined using an MTT assay. UV–Vis spectrum of Hh-AuNPs, Sa-AuNPs, Tv-AuNPs and Tt-AuNPs disclosed absorption peaks at wavelengths of 5 6 0 ± 5 nm, 5 7 0 ± 5 nm, 5 5 0 ± 5 nm and 5 4 0 ± 5 , respectively. TEM image illustrated a spherical shape of Phyto-AuNPs with particle sizes of under 100 nm. Phyto-AuNPs demonstrated more antioxidant activities than the plant extracts alone. Moreover, Phyto-AuNPs indicated higher cytotoxic activities against MCF-7 and MDA-MB-231 cell lines compared to plant extracts. This report provides new possibilities for using the above-mentioned aqueous extracts for the green synthesis of AuNPs, which may be applied to future animal breast cancer models or one step higher clinically for breast cancer patients. In the present study, gold nanoparticles (AuNPs) were synthesized using aqueous extracts of Hedra helix, Senna alexandrina, Thyme vulgaris, and Tribulus terrestris, separately. The primary goal of the study was comparing antioxidant and cytotoxic properties of biosynthesized Phyto-AuNPs with plant extracts. These Phyto-AuNPs displayed superior antioxidant and cytotoxicity properties in comparison with the plant extracts. [ABSTRACT FROM AUTHOR]

Whilst the synthesis of magnetic nanoparticles via the non‐aqueous thermal decomposition method has proven to lead to the most defined products, the tailoring of their properties is still largely achieved empirically, in particular for metal oxide nanoparticles. In this paper, the influence of ligands with varying length and concentration on the properties of the resulting magnetic nanoparticles is studied, and it is shown that the reaction temperature rather than the ligand length or concentration crucially influences the properties in various ways. The obtained particles are characterized with regard to their size, morphology, crystallinity, and magnetic characteristics, using techniques like transmission electron microscopy (TEM), X‐ray diffraction (XRD), and superconducting quantum interference device (SQUID) magnetometry measurements. It is thereby shown that the optimum choice of ligand and synthesis conditions not only serves to ensure monodispersity of the resulting particles but also to realize high colloidal stability and redispersibility. [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]

Nanomaterial synthesis is a growing study area because of its extensive range of uses. Nanoparticles' high surface‐to‐volume ratio and rapid interaction with various particles make them appealing for diverse applications. Traditional physical and chemical methods for creating metal nanoparticles are becoming outdated because they involve complex manufacturing processes, high energy consumption, and the formation of harmful by‐products that pose major dangers to human health and the environment. Therefore, there is an increasing need to find alternative, cost‐effective, dependable, biocompatible, and environmentally acceptable ways of producing nanoparticles. The process of synthesizing nanoparticles using microbes has become highly intriguing because of their ability to create nanoparticles of varying sizes, shapes, and compositions, each with unique physicochemical properties. Microbes are commonly used in nanoparticle production because they are easy to work with, can use low‐cost materials, such as agricultural waste, are cheap to scale up, and can adsorb and reduce metal ions into nanoparticles through metabolic activities. Biogenic synthesis of nanoparticles provides a clean, nontoxic, ecologically friendly, and sustainable method using renewable ingredients for reducing metals and stabilizing nanoparticles. Nanomaterials produced by bacteria can serve as an effective pollution control method due to their many functional groups that can effectively target contaminants for efficient bioremediation, aiding in environmental cleanup. At the end of the paper, we will discuss the obstacles that hinder the use of biosynthesized nanoparticles and microbial‐based nanoparticles. The paper aims to explore the sustainability of microorganisms in the burgeoning field of green nanotechnology. [ABSTRACT FROM AUTHOR]

The current situation involves an increase in interest in nanotechnology, in particular the ways in which it can be applied in the commercial and medical fields. However, traditional methods of synthesizing nanoparticles have some drawbacks, including the generation of harmful byproducts, high energy consumption, and cost. As a result, researchers have shifted their focus to "green" nanoparticle synthesis to circumvent these drawbacks. Because of their exceptional physiochemical properties, silver nanoparticles (Ag Nps) are the noble metal nanoparticles that are used most frequently. The green approach to Ag NP synthesis is environmentally friendly, non‐toxic, and cost‐effective, and it makes use of a variety of biological entities. Cyanobacteria, in particular, have garnered the most attention because of the abundance of bioactive substances that they contain, which serve both as reducing agents and as stabilizing agents during the process of biosynthesis. This review article discusses the current state of cyanobacteria‐mediated Ag NP synthesis, the potential mechanisms that are involved, nanoparticle characterization, the various applications of Ag NP in different fields, and their prospects. [ABSTRACT FROM AUTHOR]

Enormous advances have been made in the synthesis of metal nanoparticles (NPs) affording a high degree of control over their size, shape, and composition. In recent years, a growing effort has been dedicated to incorporating principles of green chemistry in different aspects of NPs, ranging from reagents/solvents to their fate in the environment. In this report, we focus on the use of Cyrene (dihydrolevoglucosenone) as an alternative green solvent for the synthesis of metal NPs. We begin with the synthesis of Ag NPs, given their prominence in the literature. Through control reactions, we show that Cyrene has a dual role of solvent and reducing agent. Additionally, the conversion yield for the Ag NPs synthesis was studied with respect to temperature and the Ag precursor. We then expand on the synthetic methodology to access Pd, Pt, and Bi NPs. The functionality of the synthesized NPs is assessed by employing them as electrocatalysts for furfural reduction and the hydrogen evolution reaction. We envision the use of Cyrene as a green solvent can be extended toward the synthesis of NPs of other metals and classes of materials. [ABSTRACT FROM AUTHOR]

Green synthesis of metal nanoparticles is a promising approach to producing nanoparticles using natural and environmentally friendly resources. It involves the use of various biological agents such as fungi, bacteria, algae, and plants. This method avoids the use of toxic chemicals and reduces the environmental impact of conventional methods of nanoparticle synthesis. Green synthesis of silver nanoparticles (AgNPs) has potential applications in biomedical, environmental, and industrial fields. Conventional coffee brewing techniques produce large quantities of spent coffee grounds that contain bioactive compounds. Silver nano-rods (AgNRs) have been synthesized from filter coffee waste. This is the first report about the synthesis of AgNRs shape from spent coffee ground (SCG). The reduction of Ag (I) to Ag (0) was achieved by spent coffee ground aqueous extract. The obtained nanostructures were characterized by ultraviolet spectroscopy (UV-Vis), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). They showed a SPR band at a wavelength of 445 nm. The SEM images demonstrated that AgNRs generally contained a rod shape and average size of 100 nm. Elemental composition of AgNRs was analyzed by EDX. A strong peak was observed at around 3 and 3.5 keV. X-ray diffraction (XRD) patterns revealed the crystalline structure of AgNRs. The shape or size of the nanoparticles has an important role in all nanotechnology applications. It was presented a perspective for usage of spent coffee as a valuable material with great potential of application in medicine, pharmacy, and electronic industries. Green synthesized AgNRs from spent coffee may become promising candidates for nano opto-electronics and nanosensors due to their conductivity. [ABSTRACT FROM AUTHOR]

Essential metal ions, such as gold, zinc, copper, cadmium, silver, titanium, and platinum, play crucial roles in maintaining physiological functions in the human body. The ability of β-cyclodextrin (β-CD) to enhance the therapeutic performance of drugs loaded onto metal and soft metal ion nanoparticles (NPs) has been highlighted, underscoring its significance in nanomedicine. This review article focuses on investigating the production process of these NPs and their potential benefits. β-CDs have emerged as desirable building blocks for creating metal and soft metal ion NPs, enhancing the solubility, stability, and bioavailability of inorganic NPs. These agents improve drug characteristics by forming inclusive compounds with drugs, effectively addressing the challenge of low drug loading capacity associated with metal and soft metal NPs. Cyclodextrins (CDs) function as stabilising agents in metal NPs during their creation, reducing agglomeration and ensuring colloidal stability. This review provides valuable insights into the potential applications of metal and soft metal ion NPs functionalized with β-CD in the biomedical domain and paves the way for advancements in NP-based drug delivery systems. [ABSTRACT FROM AUTHOR]

The process of noble metal nanoparticle synthesis is complex and consists of at least two steps: slow nucleation and fast autocatalytic growth. The kinetics of these two processes depends on the reductant "power" and the addition of stabilizers, as well as other factors (e.g., temperature, pH, ionic strength). Knowing these parameters, it is possible to synthesize materials with appropriate physicochemical properties, which can be simply adjusted by the type of the used metal, particle morphology and surface property. This, in turn, affects the possibility of their applications in various areas of life, including medicine, catalysis, engineering, fuel cells, etc. However, in some cases, the standard route, i.e., the chemical reduction of a metal precursor carried out in the batch reactor, is not sufficient due to problems with temperature control, properties of reagents, unstable or dangerous intermediates and products, etc. Therefore, in this review, we focused on an alternative approach to their chemical synthesis provided by microreactor systems. The use of microreactors for the synthesis of noble metal nanomaterials (e.g., Ag, Au, Pt, Pd), obtained by chemical reduction, is analyzed, taking into account investigations carried out in recent years. A particular emphasis is placed on the processes in which the use of microreactors removed the limitations associated with synthesis in a batch reactor. Moreover, the opportunities and challenges related to the synthesis of noble nanomaterials in the microreactor system are underlined. This review discusses the advantages as well as the problems of nanoparticle synthesis in microreactors. [ABSTRACT FROM AUTHOR]

Bergenia ciliata (BC) is a perennial herb that is frequently used as a traditional medicine. Its leaves and rhizomes are reported to have significant antioxidant, metal-reducing, and chelating properties. Although the rhizomes have the potential to synthesize silver nanoparticles (AgNPs), the leaves are yet to be studied for the green synthesis of metal nanoparticles. Likewise, photoirradiation also plays a significant role in the green synthesis of metal nanoparticles. In the current study, we intended to demonstrate the implications of photoirradiation by white light-emitting diode (LED) on the aqueous and methanol extracts (AE and ME, respectively) of BC leaf-mediated green synthesis of AgNPs. In this regard, the AgNP synthesis of the two extracts was performed in the dark and under 250-lumen (lm) and 825 lm LED bulbs. The physicochemical characterization of the synthesized nanoparticles was also performed, wherein percent nanoparticles yield, morphology of the nanoparticles, shape, size, percent elemental composition, crystallinity, and nanoparticle stability were studied. The nanoparticle-synthesizing potential of the two extracts contradicted significantly in the presence and absence of light, while the AE produced a significantly high number of nanoparticles in the dark (17.26%), and increasing light intensities only attenuated the nanoparticle synthesis, whereas ME synthesized comparatively negligible silver nanoparticles in the dark (1.23%). However, increasing light intensities significantly enhanced the number of nanoparticles synthesized in 825 lms (7.41%). The GCMS analysis further gave a comparative insight into the phytochemical composition of both extracts, wherein catechol and pyrogallol were identified as major reducing agents for nanoparticle synthesis. The influence of light intensities on the physiochemical characterization of AgNPs was predominant. While the size of both the AE- and ME-mediated AgNPs increased considerably (20–50 nm diameter) with increasing light intensities, the percent of silver atoms decreased significantly with increasing light intensities in both the AE- and ME-mediated AgNPs with ranges of 13–18% and 14–24%, respectively. The nanoparticle stability studies suggested that both the AE- and ME-mediated AgNPs were stable for up to 15 days when stored at 4 °C. The stability of both nanoparticles was attributed to the presence of a wide range of phytochemicals. In conclusion, the AE of BC leaves was reported to have significantly higher AgNP-synthesizing potential as compared to the ME. However, AE-mediated AgNP synthesis is attenuated by photoirradiation, whereas ME-mediated AgNP synthesis is enhanced by photoirradiation. The photoirradiation by white LED light increases the size of the AgNPs, while the percent silver composition declines, irrespective of the extract type. Both extracts, however, have nanoparticle stabilizing potential, thereby producing stable nanoparticles. [ABSTRACT FROM AUTHOR]

The optimization of nanomaterial synthesis using numerous synthetic variables is considered to be an extremely laborious task because conventional combinatorial explorations are prohibitively expensive. In this work, an autonomous experimentation platform developed for the bespoke design of metal nanoparticles (NPs) with targeted optical properties is reported. This platform operates in a closed‐loop manner between the batch synthesis module of metal NPs and the UV–vis spectroscopy module, based on the feedback of the AI optimization modeling. With silver (Ag) NPs as a representative example, it is demonstrated that the Bayesian optimizer implemented with the early stopping criterion can efficiently produce Ag NPs at room temperature precisely possessing the desired absorption spectra within only 200 iterations (when optimizing among five aqueous synthetic reagents). In addition to the outstanding material developmental efficiency, the analysis of synthetic variables further reveals a novel chemistry involving the quantitative effects of citrate in Ag NP synthesis. The amount of citrate is key to controlling the competition between spherical and plate‐shaped NPs and, as a result, affects the shapes of the absorption spectra as well. This study highlights both capabilities of the platform to enhance search efficiencies and to provide novel chemical knowledge by analyzing datasets accumulated from autonomous experimentations. [ABSTRACT FROM AUTHOR]

Radiation chemistry enables the synthesis of colloidal nanoparticles without chemical reducing agents, yielding metal nanoparticles via simple and direct processes. Aliphatic alcohols are widely used to promote the formation of nanoparticles in radiolytic synthesis by inhibiting the reoxidation of these metal nanoparticles by scavenging hydroxyl radicals. However, the role of the scavenger has been limited to simply accelerating the formation of the nanoparticles without altering their nature. Herein, the role of radical scavengers is investigated in determining the type of metal nanoparticles formed, with the scavenger concentration playing a crucial role. It is found that the addition of isopropyl alcohol controls the formation of hexagonal close‐packed (hcp) palladium hydride (PdHx) nanoparticles that are previously synthesized for the first time via radiation chemistry by increasing the concentrations of hydrated electrons and hydrogen radicals. This discovery reveals a more active role for radical scavengers in radiolytic syntheses, and this strategy can be used for the cost‐effective mass production of hcp PdHx nanoparticles. [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]

Study of nanoparticles has attracted the immense attention of researchers because of their wide applications in the medicine, chemical industries, and biotechnology. This paper highlights that plants and microbes can be a source of bio-compounds in nanoparticle synthesis in place of toxic chemicals. As this is an environmentally friendly approach following the principles of green synthesis which is cheap and is not toxic. Both sources provide antioxidant, anticancer, and antimicrobial properties which hold great importance in the manufacturing of NPs. This review aims to bring together the diversity of synthesized metallic nanoparticles mediated by plant extracts, fungi, algae, bacteria and yeasts. All the mentioned bio-resources contain biomolecule which includes protein and enzyme which serves the twin action of both reduction and capping of the synthesized nanoparticles. The synthesized NPs are characterized by using UV-visible spectrometry, FT-IR, XRD, TEM, SEM and EDX. Also, the biomedical application of the synthesized NPs is explored in the treatment of cancer. [ABSTRACT FROM AUTHOR]

The use of biosynthesis is considered an environmentally friendly and more sustainable method for the production of metal nanoparticles. In this study, copper nanoparticles (Cu-NPs) were synthesized using tea stem extract as a reducing agent. Spectroscopic identification revealed that the CuO is the major crystalline structure with a particle size of 14.9 nm. The Bg mode of the Raman active mode is associated with the symmetric oxygen stretching of Cu-O and is consistent with the monoclinic crystal CuO in X-ray powder diffraction (XRD) measurement. X-ray photoelectron spectrometer (XPS) deconvolution revealed the split peaks for Cu 2p3/2 and confirmed the coexistence of Cu+ and Cu2+ in the Cu-NPs. The Cu-NPs possessed effective catalytic ability for the degradation of methylene blue (MB) from the aqueous phase in a Fenton-like system. These results provide important evidence for the potential application of tea stem in synthesis of nanoparticle. [ABSTRACT FROM AUTHOR]

This study evaluated the efficacy of phytogenic silver and zinc nanoparticles in improving heat resilience in various wheat varieties. The silver and zinc nanoparticles were synthesized using plant leaf extract and characterized using various techniques. Four wheat varieties (DBW187, Black Wheat, DBW 50, and PBW 621) were subjected to field trials. The random block design was used, and nanoparticles in different concentrations were applied at various growth stages and morphologically, and yield parameters were recorded. UV–vis spectroscopy spectral analysis showed peaks for Ag nanoparticles at 420 nm wavelength and Zn nanoparticles at 240 and 350 nm wavelength, depicting the preliminary confirmation of nanoparticle synthesis. Electron microscopic analysis (TEM and SEM) provided morphological insights and confirmed synthesis of fine-sized particle mostly in a range between 10 and 60 nm. Energy dispersive x-ray analysis confirmed the elemental composition of the synthesized nanoparticles, with Ag and Zn elements detected in their respective samples. It also confirmed the oxide nature of synthesized ZnNPs. Dynamic light scattering analysis provided size distribution profiles, indicating average sizes of approximately 61.8 nm for Ag nanoparticles and 46.5 nm for Zn nanoparticles. The concentrations of Ag and Zn nanoparticles in the samples were found to be 196.3 ppm and 115.14 ppm, respectively, through atomic absorption spectroscopic analysis. Fourier transform infrared spectroscopy analysis revealed characteristic functional groups present in the nanoparticles. The results of field experiments established that Ag nanoparticles at 75 ppm concentration exhibited the most significant enhancements in plant growth. Conversely, Zn nanoparticles at a 100 ppm concentration demonstrated the most substantial improvements in the growth and yield of heat-stressed wheat varieties. The study concludes that optimized concentrations of silver and zinc nanoparticles can effectively improve heat stress resilience in wheat. These findings are promising to enhance abiotic stress resilience in crops. [ABSTRACT FROM AUTHOR]

In recent years, the utilization of extremophile microorganisms for the synthesis of metal nanoparticles, featuring enhanced properties and diverse compositions, has emerged as a sustainable strategy to generate high-quality nanomaterials with unique characteristics. Our study focuses on the biosynthesis of Cu-In-S (CIS) nanoparticles, which has garnered considerable attention in the past decade due to their low toxicity and versatile applications in biomedicine and solar cells. Despite this interest, there is a notable absence of reports on biological methods for CIS nanoparticle synthesis. In this research, three yeast species were isolated from soil samples in an extreme Antarctic environment—Union Glacier, Ellsworth Mountains. Among these isolates, Filobasidium stepposum demonstrated the capability to biosynthesize CIS nanoparticles when exposed to copper sulfate, indium chloride, glutathione, and cysteine. Subsequent purification and spectroscopic characterization confirmed the presence of characteristic absorbance and fluorescence peaks for CIS nanoparticles at 500 and 650 nm, respectively. Transmission electron microscopy analysis revealed the synthesis of monodisperse nanoparticles with a size range of 3–5 nm. Energy dispersive X-ray spectroscopy confirmed the composition of the nanoparticles, revealing the presence of copper, indium, and sulfur. The copper/indium ratio ranged from 0.15 to 0.27, depending on the reaction time. The biosynthesized CIS nanoparticles showed higher photostability than biomimetic nanoparticles and demonstrated successful application as photosensitizers in quantum dot-sensitized solar cells (QDSSC), achieving a conversion efficiency of up to 0.0247%. In summary, this work presents a cost-effective, straightforward, and environmentally friendly method for CIS nanoparticle synthesis. Furthermore, it constitutes the first documented instance of a biological procedure for producing these nanoparticles, opening avenues for the development of environmentally sustainable solar cells. [ABSTRACT FROM AUTHOR]

Nanotechnology has been developing tremendously since the 1970s. Various types of nanoparticles such as carbon, metal, bio-originated, etc. have been synthesized by a variety of physical, chemical and biological methods. Biological methods which employ bacteria, fungi and plants for the synthesis of metal nanoparticles are found to be a sustainable and eco-friendly approach. Among biological methods, plants being a cleaner and greener source are widely accepted. The present work includes screening the synthesis of silver nanoparticles using the roots and leaves extract of 15 different Indian Crinum species, optimization, characterization and kinetic studies of silver nanoparticles. Among all the species, the highest synthesis was observed by Crinum moorei which was detected by apeak at 390 nm in UV–visible spectrophotometry. The optimization of silver nanoparticle synthesis from C. moorei roots was performed based on extract concentration (1 %), salt concentration (1.5 mM), pH (9) and temperature (30°C). The kinetics study of silver nanoparticles showed a rate constant of 0.0609 h−1. Furthermore, the characterization of synthesized silver nanoparticles was conducted using TEM, SEM, FTIR, XRD, NTA and DLS. These synthesized AgNPs exhibited catalytic activity for Congo red dye decolorization, which could serve as an initiative for the further studies to control the environmental pollution caused by dyes and colorants. [Display omitted] • First report of synthesis of AgNPs using root extracts of Crinum moorei. • Characterization of synthesized AgNPs using UV-visible spectroscopy, FESEM, TEM, NTA, XRD and FTIR. • Kinetics of synthesis of AgNPs. • Catalytic activity of AgNPs in degradation of Congo red. [ABSTRACT FROM AUTHOR]

The evolution and rapid spread of multidrug-resistant (MDR) bacterial pathogens have become a major concern for human health and demand the development of alternative antimicrobial agents to combat this emergent threat. Conventional intracellular methods for producing metal nanoparticles (NPs) using whole-cell microorganisms have limitations, including binding of NPs to cellular components, potential product loss, and environmental contamination. In contrast, this study introduces a green, extracellular, and sustainable methodology for the bio-materialization of silver NPs (AgNPs) using renewable resource cell-free yeast extract. These extracts serve as a sustainable, biogenic route for both reducing the metal precursor and stabilizing the surface of AgNPs. This method offers several advantages such as cost-effectiveness, environment-friendliness, ease of synthesis, and scalability. HR-TEM imaging of the biosynthesized AgNPs revealed an isotropic growth route, resulting in an average size of about ~ 18 nm and shapes ranging from spherical to oval. Further characterization by FTIR and XPS results revealed various functional groups, including carboxyl, hydroxyl, and amide contribute to enhanced colloidal stability. AgNPs exhibited potent antibacterial activity against tested MDR strains, showing particularly high efficacy against Gram-negative bacteria. These findings suggest their potential role in developing alternative treatments to address the growing threat of antimicrobial resistance. Additionally, seed priming experiments demonstrated that pre-sowing treatment with AgNPs improves both the germination rate and survival of Sorghum jowar and Zea mays seedlings. Key points: •Yeast extract enables efficient, cost-effective, and eco-friendly AgNP synthesis. •Biosynthesized AgNPs showed strong antibacterial activity against MDR bacteria. •AgNPs boost seed germination and protect against seed-borne diseases. [ABSTRACT FROM AUTHOR]

With the rapid advancement in the field of nanotechnology, the use of toxic chemicals can be eliminated with the help of certain medicinal plants which has a significant role for a better future in terms of nanoparticle synthesis and are known for their potent activity due to the presence of bioactive components. Owing to the large surface to volume ratio of the nanoparticles, they have been of immense importance for their effective utilization in various sectors such as in medicine, pharmaceutical, food industry and pharmaceutical sector. Recently several research findings has suggested the role of plants as an excellent source for the formation of nanoparticles as it requires less time and impose no threat to the environment. Therefore, the present review focuses on the methods of synthesis of AgNPs, ZnNPs, AuNPs which are mostly mediated by bacteria, fungi and different parts of the plant extracts and their possibility of usage in the field of biomedical sector anddiscusses it role in the drug delivery process. Furthermore, more detailed research and an in depth understanding on the assays has to be performed for getting the information about the toxicity of these nanoparticles. [ABSTRACT FROM AUTHOR]

Technological progress has led to the development of analytical tools that promise a huge socio-economic impact on our daily lives and an improved quality of life for all. The use of plant extract synthesized nanoparticles in the development and fabrication of optical or electrochemical (bio)sensors presents major advantages. Besides their low-cost fabrication and scalability, these nanoparticles may have a dual role, serving as a transducer component and as a recognition element, the latter requiring their functionalization with specific components. Different approaches, such as surface modification techniques to facilitate precise biomolecule attachment, thereby augmenting recognition capabilities, or fine tuning functional groups on nanoparticle surfaces are preferred for ensuring stable biomolecule conjugation while preserving bioactivity. Size optimization, maximizing surface area, and tailored nanoparticle shapes increase the potential for robust interactions and enhance the transduction. This article specifically aims to illustrate the adaptability and effectiveness of these biosensing platforms in identifying precise biological targets along with their far-reaching implications across various domains, spanning healthcare diagnostics, environmental monitoring, and diverse bioanalytical fields. By exploring these applications, the article highlights the significance of prioritizing the use of natural resources for nanoparticle synthesis. This emphasis aligns with the worldwide goal of envisioning sustainable and customized biosensing solutions, emphasizing heightened sensitivity and selectivity. [ABSTRACT FROM AUTHOR]

Both the size and crystallinity should be optimized for practical applications utilizing metallic nanoparticles because they strongly influence the nanoparticles property. Herein a liquid phase chemical reduction method controls the defects (crystallinity) in metallic Cu nanoparticles simply and easily. Although the addition of an impurity substance, which cannot be thermodynamically alloyed with Cu, reduces the crystallinity of synthesized Cu nanoparticles, it also affects the deposition behavior, and consequently, the nanoparticle size changes unexpectedly. Therefore, a precise control of the synthesis condition is required to synthesize the nanoparticles having optimal size and crystallinity. To clarify the nanoparticle formation mechanism in an impurity-containing solution, the catalytic activity of the reductant and the redox potential change due to the metastable product are electrochemically evaluated to reveal the correlation between nanoparticle formation behavior and synthesis condition. Finally, the synthesis of two types of Cu nanoparticles, which have similar sizes but different crystallinities is demonstrated. This simple nanomaterial design approach to control the crystallinity and the interpretation of the deposition process in an impurity-containing condition should be widely applicable to metallic nanoparticle syntheses. [ABSTRACT FROM AUTHOR]

The green approach-based nanoparticle synthesis is considered a more cost-effective and ecologically responsible method of producing nanoparticles than other standard techniques. A major accomplishment in resolving these issues is the use of nanoparticles for environmental pollution remediation. This article describes a simple method for producing MgO and ZnO nanoparticles (NPs) using aqueous extracts of Zingiber officinale and Glycyrrhiza roots as the stabilizing and reducing agents, respectively. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersed X-ray (EDX) spectroscopy methods were used to characterize the biologically synthesized metal oxide nanoparticles (MO NPs). The XRD results showed that the mean crystallite sizes of synthesized ZnO and MgO NPs, which have excellent purity, are 12.35 nm and 4.83 nm, respectively. The spherical or elliptical shape of the synthesized NPs was confirmed by the SEM analysis. The antibacterial activity of the synthesized NPs against both Gram-negative and Gram-positive bacteria was thoroughly investigated. With a medium zone of inhibition of 7 to 10 mm, the as-synthesized MgO NPs and ZnO NPs demonstrated moderate antibacterial activity towards various bacterial strains. [ABSTRACT FROM AUTHOR]

Due to their optical properties (localized surface plasmon resonance, LSPR), colloidally dispersed metal nanoparticles are well suited for selective heating by high‐energy laser radiation above their melting point without being limited by the boiling point of the solvent, which represents an excellent complement to wet‐chemical nanoparticle synthesis. By combining wet‐chemical synthesis and postsynthesis laser treatment, the advantages of both methods can be used to specifically control the properties of nanoparticles. Especially in the colloidal synthesis of nanoalloys consisting of two or more metals with different redox potentials, wet‐chemical synthesis quickly reaches its limits in terms of composition control and homogeneity. For this reason, the direct synthesis path is divided into two parts to take the strengths of both methods. After preparing Au–Cu hetero nanoparticles by wet‐chemical synthesis, nanoalloys with previous adjusted composition can be formed by postsynthesis laser treatment. The formation of these nanoalloys can be followed by different characterization methods, such as transmission electron microscopy (TEM), where the fusion of both metal domains and the formation of spherical and homogeneous Au–Cu nanoparticles can be observed. Moreover, the alloy formation can be followed by different shifts of X‐ray diffraction (XRD) reflections and LSPR maxima depending on the composition. [ABSTRACT FROM AUTHOR]

In the most recent few years, there has been a significant uptick in curiosity regarding the process of manufacturing metal oxide nanoparticles by making use of the extract of various plant components. The generated iron oxide nanoparticles demonstrate validity for use in biomedical applications. In the work that we are presenting here, we use the extract of Nigella sativa seeds to carry out an environmentally friendly iron oxide nanoparticle synthesis (Fe2O3 NPs). Advanced diagnostic tools such as scanning electron microscopy (SEM), Fourier transform infrared (FTIR) analysis, X-ray diffraction (XRD) investigation, and others were utilized in order to perform structural characterization on the generated Fe2O3 NPs. According to the preliminary findings, the particles have a semispherical form with an average particle size that falls between 15 nm and 20 nm. Phytochemicals, particularly polyphenols, are extremely important contributors to the production of iron oxide nanoparticles. Since the findings of the antimicrobial investigation were highly encouraging, the antimicrobial activity of the iron oxide particles that were created was investigated to see if they might inhibit the growth of specific bacterial and fungal pathogens. [ABSTRACT FROM AUTHOR]

The fabrication of thin-film electrodes, which contain metal nanoparticles and nanostructures for applications in electrochemical sensing as well as energy conversion and storage, is often based on multi-step procedures that include two main passages: (i) the synthesis and purification of nanomaterials and (ii) the fabrication of thin films by coating electrode supports with these nanomaterials. The patterning and miniaturization of thin film electrodes generally require masks or advanced patterning instrumentation. In recent years, various approaches have been presented to integrate the spatially resolved deposition of metal precursor solutions and the rapid conversion of the precursors into metal nanoparticles. To achieve the latter, high intensity light irradiation has, in particular, become suitable as it enables the photochemical, photocatalytical, and photothermal conversion of the precursors during or slightly after the precursor deposition. The conversion of the metal precursors directly on the target substrates can make the use of capping and stabilizing agents obsolete. This review focuses on hybrid platforms that comprise digital metal precursor ink printing and high intensity light irradiation for inducing metal precursor conversions into patterned metal and alloy nanoparticles. The combination of the two methods has recently been named Print-Light-Synthesis by a group of collaborators and is characterized by its sustainability in terms of low material consumption, low material waste, and reduced synthesis steps. It provides high control of precursor loading and light irradiation, both affecting and improving the fabrication of thin film electrodes. [ABSTRACT FROM AUTHOR]

In recent years, nanomaterials have attracted the research intervention of experts in the fields of catalysis, energy, biomedical testing, and biomedicine with their unrivaled optical, chemical, and biological properties. From basic metal and oxide nanoparticles to complex quantum dots and MOFs, the stable preparation of various nanomaterials has always been a struggle for researchers. Microfluidics, as a paradigm of microscale control, is a remarkable platform for online stable synthesis of nanomaterials with efficient mass and heat transfer in microreactors, flexible blending of reactants, and precise control of reaction conditions. We describe the process of microfluidic preparation of nanoparticles in the last 5 years in terms of microfluidic techniques and the methods of microfluidic manipulation of fluids. Then, the ability of microfluidics to prepare different nanomaterials, such as metals, oxides, quantum dots, and biopolymer nanoparticles, is presented. The effective synthesis of some nanomaterials with complex structures and the cases of nanomaterials prepared by microfluidics under extreme conditions (high temperature and pressure), the compatibility of microfluidics as a superior platform for the preparation of nanoparticles is demonstrated. Microfluidics has a potent integration capability to combine nanoparticle synthesis with real-time monitoring and online detection, which significantly improves the quality and production efficiency of nanoparticles, and also provides a high-quality ultra-clean platform for some bioassays. [ABSTRACT FROM AUTHOR]

Multi-resistant bacteria isolated in clinical centers currently constitute one of the most serious health problems worldwide. Multiple therapeutic alternatives are investigated, especially the use of nanomaterials. Metallic nanoparticles have been investigated for many years. One of the most relevant properties is their antibacterial capacity. However, few studies associate this property with bacteria isolated from clinical infections. In this study, the antimicrobial activity of AgNPs and CeO2NPs against clinically important bacteria such as S. aureus, P. aeruginosa, and A. baumannii, from clinical origin, was evaluated. The synthesis of nanoparticles is presented through a green synthesis method with the use of tannic acid as a reducing agent. The characterization of the nanoparticles was carried out using UV-Vis spectrum, Transmission Electron Microscopy, Dynamic Light Scattering and X-ray diffraction. The antibacterial effect against strains of clinical origin was evaluated using the agar diffusion technique, where a wide range of spectrum of activity for AgNPs. This study shows the importance of generating biological assays obtaining strains of clinical origin due to their great diversity and complexity in relation to the use of known bacterial strains, particularly if the new therapies under study are synthesized as an alternative to the antimicrobials currently used. [ABSTRACT FROM AUTHOR]

Approaches to synthesis of Ag, Cu nanoparticles in liquid matrices and on the surface of both organic and inorganic powders and granules of different dispersity for biomedical purposes were analyzed. The advantages of nanoparticle synthesis by the methods of physical deposition in vacuum over the methods of chemical and hybrid synthesis are given. The high effectiveness and advantage of deposition from the evaporator with a directed vapour flow in vacuum are shown, compared to the classical crucible evaporation scheme. Optimal technological modes of deposition from the evaporator were established for achieving uniformity of the directed vapour flow. The dependence between the target temperature, efficiency of the evaporation scheme and evaporator to target distance was experimentally determined. [ABSTRACT FROM AUTHOR]