Stable Silver Nanoparticles Research Articles

A facile and greener approach for synthesis of lignin capped-silver nanoparticles (LS-AgNPs) and assessment of their antibacterial and antioxidant properties

Silver nanoparticles have garnered significant attention in research due to their numerous advantageous qualities, such as antimicrobial, antioxidant, and anticancer activities. Several methods have been employed previously to produce these nanoparticles, but green synthesis has gained prominence due to its lack of harmful by-products. In this study, stable and biocompatible lignin-capped silver nanoparticles (LS-AgNPs) have been synthesized using a green approach that utilized nontoxic sodium lignosulfonate as both the reducing and capping agents. Various process parameters, such as pH, temperature, time, and raw material concentration have been optimized to simplify, accelerate and mould the synthesis activity easy and eco-friendly. The morphology and dimensions of the prepared lignin-capped silver nanoparticles (LS-AgNPs) have been characterized using UV–Vis spectroscopy, particle size analyser, X-ray diffraction analysis, Fourier transform infrared spectroscopy and Transmission Electron Microscopy. The produced nanoparticles have an average diameter of 24 nm and a FCC crystalline structure that is capped with lignin components. MBC of LS-AgNPs has been found 4 and 6 ppm against S. aureus and E. coli bacteria, respectively. The IC50 value for antioxidant property has been found 34.37 μg/mL. In summary, the prepared LS-AgNPs have exhibited a synergistic effect resulting from the combination of lignosulfonate and silver particles. The synergistic effect not only enhances antimicrobial activity and antioxidant property remarkably, this approach enables the utilization of biobased silver nanoparticles for various applications with its requirement of minimal quantity to have much lowered toxicity compared to pure silver nanoparticles.

Optical Study of Desmodium Elegan Mediated Silver Nanoparticles Using Tauc’s Equation

Green synthesis of metallic nanoparticles is more eco-friendly, simpler, and nontoxic as compared to chemical synthesis. Due to their thermal stability and good electrical conduction silver nanoparticles have significant importance these days. In the present work, the stable silver nanoparticles were prepared from the aqueous solution of AgNO3 by green synthesis technique in which the Desmodium elegan plant extract was used as a reducing and capping agent to convert Ag+ to Ag0. A UV-visible spectrometer is used in the range of 200 nm to 800 nm with a scanning speed of 200 nm per minute, the absorption band is found at a 450 nm peak that indicates the synthesis of silver nanoparticles. The particle size of the nanoparticles was in the range of 11 nm to 70 nm with an average of 45 nm and a spherical shape. Further confirmation of nano size, scanning electron microscopy (SEM) was also utilized for the size distribution and shape of the synthesized nanoparticles. The synthesized nanoparticles SEM studies show irregular spherical morphology with polydispersed trend and the average particle size was found at 45 nm. The absorption band for the synthesized sample was found at 450 nm peak. The bandgap energy was 2.84 eV estimated by Tauc’s equation. This indicates that the synthesized nanoparticles electrically lie in the range of semiconductors and can be used as a biosensor. This synthesis technique is a nontoxic technique so these particles may be used for water treatment.

Bio-synthesized AGS@AgNPs for wound healing, antioxidant support, antibacterial defense, and anticancer intervention

Slow wound healing and wound infections are significant challenges for burn patients. Biosynthesis of nanoparticles (NPs) using plant extracts offers a rapid, facile, and safe method for producing biocompatible NPs. In this study, Anethum graveolens seed (AGS) extract served as a masking and reducing agent for the synthesis of silver nanoparticles (AGS@AgNPs). Initially, the parameters influencing AGS@AgNPs synthesis, including silver nitrate concentration, reaction time, temperature, and pH, were optimized. Subsequently, AGS@AgNPs structural and biological characteristics were evaluated. Observation of the surface plasmon resonance (SPR) of the AGS@AgNPs at approximately 420 nm, accompanied by a color change of the suspension to dark brown, confirmed AGS@AgNPs synthesis. Analysis via X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), zeta potential, and transmission electron microscopy (TEM) confirmed the production of pure, homogeneous, spherical, and stable silver NPs with sizes ranging from 20 to 40 nm using Anethum graveolens extract. Antibacterial assays revealed significant activity against both Gram-positive and Gram-negative bacterial strains. Antioxidant assessments demonstrated that AGS@AgNPs at a concentration of 250 μg/ml exhibited 92% inhibition of DPPH free radicals and in FRAP test, A. graveolens seed extract and AGS@AgNPs reduced Fe3+ ions to Fe2+ by 48.7% and 73.1%, respectively. Investigation of anticancer properties against the lung cancer cell line (A-549) revealed an IC50 value of 242 μg/ml. The results of the flow cytometry test and lactate dehydrogenase (LDH) assay demonstrated the death of cancer cells. Moreover, wound healing assays demonstrated a significant acceleration in burn wound closure rates in rats on days 3, 7, and 14 following treatments with AGS@AgNPs. Overall, these findings highlight the favorable biological activities of AGS@AgNPs, suggesting their potential utility in nanomedicine applications.

Enhanced antibacterial effect of natural tannin stabilized silver nano particles against human pathogens: A target toward FtsZ proteins

BackgroundTannins are the polyphenolic group of plant compounds having strong antimicrobial potential. Research on human pathogens using silver nanoparticles for antimicrobial purposes has opened up new possibilities in nanomedicine. ObjectiveThe present study was concerned with combining the effectiveness of the two by the green synthesis of silver nanoparticles with plant tannin. MethodsSynthesis of silver nanoparticles was done based on the tannin content of the selected plants. Characterization of the synthesized nanoparticles has been performed through UV–VIS, FTIR spectroscopy, Zeta potential, XRD analysis and FEGSEM imaging. The antibacterial potentiality of the nanoparticles was checked against two most susceptible bacteria Staphylococcus epidermidis and Salmonella typhi. ResultsAmong the studied plants, Phyllanthus emblica showed highest tannin content and best bactericidal properties. The nanoparticles synthesized with P. emblica showed the highest zone of inhibition against the studied bacteria. An in-silico comparative molecular docking study of the bioactive compounds from the selected plants was performed against the FtsZ protein of S. epidermidis and YfdX protein of S. typhi. Three compounds namely Isocorilagin,1(β), 6-di-o-galloylglucose and Hamamelitannin appeared as the best inhibitors of the said proteins and among them, Isocorilagin, a natural tannin showed the best docking score of -10.2 Kcal/mol with FtsZ protein. Further molecular dynamics simulation studies of the FtsZ protein-Isocorilagin complex support its stability indicating Isocorilagin as the natural inhibitor of the pathogenic bacterial protein FtsZ. ConclusionThese results concluded that synthesis of nanoparticles with plant tannin is a cost effective green approach and the synthesised nanoparticles appear as efficient antimicrobial agent.

Solvent-based dual detection of Hg2+ and Cr3+ ions by polyvinylpyrrolidone stabilized silver nanoparticles as colorimetric sensor

Solvent-based dual detection of Hg2+ and Cr3+ ions by polyvinylpyrrolidone stabilized silver nanoparticles as colorimetric sensor

Comparison between Green and Chemical Synthesis of Silver Nanoparticles: Characterization and Antibacterial Activit

Using chemical reduction and green technology, two different approaches are used in the current work to synthesize silver nanoparticles. Pomegranate peel extract has been utilized in green technology applications. Furthermore, In the chemical approach, polyvinylpyrrolidine and ascorbic acid were utilized as reducing agents, and the optical, structural, and antibacterial characteristics of the two versions were investigated. In comparison to the chemical reduction variant (30.38 nm), the particle sizes in the green technique (19.5 nm) were smaller. Comparing green silver nanoparticles to chemically synthesized silver nanoparticles, SEM pictures showed that the former had formed a distinct crystalline shape and were evenly distributed on the surface. Granules constituted the shape of the particles. Additionally, it spreads topically. Whereas the greenly synthesized variant's absorption band was at 280 nm, the chemically synthesized variant's absorption band was at 300 nm. It was demonstrated by spectroscopic data of green silver nanoparticles that they have the capacity to produce and stabilize silver nanoparticles. Chemically produced green silver nanoparticles were also exposed to FTIR analysis to identify active functional groups. Silver particles can also be stabilized by chemically produced silver nanoparticles. To assess the antibacterial activity, the nanoparticle agar diffusion method was employed. The bacteria detected in the medium were Staphylococcus aureus and Escherichia coli. In the green form, the bacterial growth inhibition zone was larger and was produced with varying concentrations of 25 ml, 50 ml, 75 ml, and 100 ml, or 13 ml, 10 ml, 9 ml, and 8 ml for Staphylococcus aureus and 15 ml, 12 ml, 10 ml, and 7 ml for E. coli, respectively. Green-produced transcripts exhibited higher antibacterial responses, which were likely caused by the faster rate of nanoparticle stabilization mechanism by organic compounds found in pomegranate fruit peel extract.

Synthesis and Characterization of Silver Nanoparticles Stabilized with Biosurfactant and Application as an Antimicrobial Agent.

Surfactants can be used as nanoparticle stabilizing agents. However, since synthetic surfactants are not economically viable and environmentally friendly, biosurfactants are emerging as a green alternative for the synthesis and stabilization of nanoparticles. Nanoparticles have been applied in several areas of industry, such as the production of biomedical and therapeutic components, packaging coating, solar energy generation and transmission and distribution of electrical energy, among others. The aim of this study was to synthesize, in a simple and green way, silver nanoparticles (AgNPs) using the biosurfactant produced by Candida lipolytica UCP 0899 as a stabilizer. AgNPs were examined and morphologically characterized using the techniques of ultraviolet-visible spectroscopy (UV-visible), scanning electron microscopy (SEM), zeta potential and energy dispersive X-ray spectroscopy (EDS). Newly formed silver nanoparticles showed a maximum UV-visible absorption peak at 400 nm, while a shift to 410 nm was observed in those stored for 120 days. SEM micrograph confirmed the formation of nanoparticles with an average size of 20 nm and with a predominant spherical structure, while a zeta potential of -60 mV suggested that the use of the biosurfactant promoted their stability. Stabilized nanoparticles were tested for their antimicrobial activity against bacterial isolates of Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli and Enterobacter sp., as well as fungal isolates of Candida albicans and Aspergillus niger. At a concentration of 16.50 µg/mL, AgNPs inhibited the growth of all target microorganisms according to the following decreasing order: E. coli (95%), S. aureus, C. albicans (90%), A. niger (85%), Enterobacter sp. (75%) and P. aeruginosa (71%). These results suggest the potential use of the biosurfactant as a stabilizer of silver nanoparticles as an antimicrobial agent in different industrial sectors. Furthermore, the in vivo toxicity potential of biosurfactants was evaluated using the Tenebrio molitor model. The larvae were treated with concentrations in the range of 2.5, 5.0 and 10 g/L, and no mortality was observed within the 24 to 72 h period, demonstrating non-toxicity within the tested concentration range. These findings support the safety, efficacy and non-toxicity of biosurfactant-stabilized nanoparticles.

Magnetic Silver Nanoparticles Stabilized by Superhydrophilic Polymer Brushes with Exceptional Kinetics and Catalysis.

Stimuli-responsive catalysts with exceptional kinetics and complete recoverability for efficient recyclability are essential in, for example, converting pollutants and hazardous organic compounds into less harmful chemicals. Here, we used a novel approach to stabilize silver nanoparticles (NPs) through magneto/hydro-responsive anionic polymer brushes that consist of poly (acrylic acid) (PAA) moieties at the amine functional groups of chitosan. Two types of responsive catalyst systems with variable silver loading (wt.%) of high and low (PAAgCHI/Fe3O4/Ag (H, L)) were prepared. The catalytic activity was evaluated by monitoring the reduction of organic dye compounds, 4-nitrophenol and methyl orange in the presence of NaBH4. The high dispersity and hydrophilic nature of the catalyst provided exceptional kinetics for dye reduction that surpassed previously reported nanocatalysts for organic dye reduction. Dynamic light scattering (DLS) measurements were carried out to study the colloidal stability of the nanocatalysts. The hybrid materials not only showed enhanced colloidal stability due to electrostatic repulsion among adjacent polymer brushes but also offered more rapid kinetics when compared with as-prepared Ag nanoparticles (AgNPs), which results from super-hydrophilicity and easy accumulation/diffusion of dye species within polymer brushes. Such remarkable kinetics, biodegradability, biocompatibility, low cost and facile magnetic recoverability of the Ag nanocatalysts reported here contribute to their ranking among the top catalyst systems reported in the literature. It was observed that the apparent catalytic rate constant for the reduction of methyl orange dye was enhanced, PAAgCHI/Fe3O4/Ag (H) ca. 35-fold and PAAgCHI/Fe3O4/Ag (L) ca. 23-fold, when compared against the as prepared AgNPs. Finally, the regeneration and recyclability of the nanocatalyst systems were studied over 15 consecutive cycles. It was demonstrated that the nanomaterials display excellent recyclability without a notable loss in catalytic activity.

Stabilization of silver nanoparticles in a transparent polymethacrylate matrix while maintaining the capabilities of a colorimetric hydrogen peroxide sensor

Stabilization of silver nanoparticles in a transparent polymethacrylate matrix while maintaining the capabilities of a colorimetric hydrogen peroxide sensor

Fabrication of Highly Stable Polyurushiol-Decorated Silver Nanoparticles and Evaluation of Their Antibacterial and Anti-Microalgae Activities

Fabrication of Highly Stable Polyurushiol-Decorated Silver Nanoparticles and Evaluation of Their Antibacterial and Anti-Microalgae Activities

Green stabilization of silver nanoparticles over the surface of biocompatible Fe3O4@CMC for bactericidal applications

The emergence of antimicrobial resistance in bacteria, especially in agents associated with urinary tract infections (UTIs), has initiated an exciting effort to develop biocompatible nanoparticles to confront their threat. Designing simple, cheap, biocompatible, and efficient nanomaterials as bactericidal agents seems to be a judicious response to this problem. Here, a solvothermal method was hired for the one-pot preparation of the cellulose gum (carboxymethyl cellulose, CMC) magnetic composite to prepare a cost-effective, efficient, and biocompatible support for the plant-based stabilization of the silver NPs. The green stabilization of the Ag NPs is performed using Euphorbia plant extract with high efficiency. Various characterization methods, including FT-IR, XRD, SEM, EDS, TEM, and VSM were used to study the composition and properties of Fe3O4@CMC/AgNPs. The composite shows well integrity and monodispersity with a mean diameter of <300 nm, indicating its potential for bio-related application. The CMC functionalities of the proposed material facilitated the stabilization of the Ag NPs, resulting in their monodispersity and enhanced performance. The manufactured composite was used as an antibacterial agent for the removal of UTIs agents, collected from 200 hospitalized patients with acute coronary syndrome, which showed promising results. This study showed that the concentration of the Ag NPs has a direct relationship with the antibacterial properties of the composite.

Stability and SERS signal strength of laser-generated gold, silver, and bimetallic nanoparticles at different KCl concentrations

Noble metal nanoparticles, specifically gold and silver, are extensively utilized in sensors, catalysts, surface-enhanced Raman scattering (SERS), and optical-electronic components due to their unique localized surface plasmon resonance (LSPR) properties. The production of these nanoparticles involves various methods, but among the environmentally friendly approaches, laser ablation stands out as it eliminates the need for toxic chemicals during purification. However, nanoparticle aggregation poses a challenge in laser ablation, necessitating the addition of extra materials that contaminate the otherwise clean process. In this study, we investigate the effectiveness of a biocompatible material, potassium chloride (KCl), in preventing particle aggregation. Although salt is known to trigger aggregation, we observed that certain concentrations of KCl can slow down this process. Over an eight-week period, we examined the aggregation rate, extinction behavior, and stability of gold, silver, and hybrid nanoparticles generated in different KCl concentrations. Extinction spectra, SEM images, SERS signal strength, and zeta potential were analyzed. Our results demonstrate that laser ablation in water and salt solutions yields nanoparticles with a spherical shape and a negative zeta potential. Importantly, we identified the optimal concentration of potassium chloride salt that maintains solution stability and SERS signal strength. Adsorbed chloride ions on silver nanoparticles were evidenced by low-frequency SERS band near 242 cm−1. A better understanding of the effect of KCl concentration on the properties of noble metal nanoparticles can lead to improved generation protocols and the development of tailored nanoparticle systems with enhanced stability and SERS activity.

Polyoxometalate-Polymer Directed Macromolecular Architectonics of Silver Nanoparticles as Effective Antimicrobials.

A novel inorganic-organic-inorganic ternary bioactive material formulated on antimicrobial peptide-based polymer has been reported. Supramolecular approach has been employed to incorporate molecularly crowded tyrosine-based polymer stabilized silver nanoparticles into membrane bound vesicles exploiting polyoxometalate-triggered surface templating strategy. Utilizing the covalent reversible addition fragmentation chain transfer (RAFT) polymerization and exploiting templated supramolecular architectonics at biopolymer interface, the bioactive ternary polymeric nanohybrids have been designed against Shigellosis leveraging the antibacterial activities of silver nanoparticle, cationic amphiphilic tyrosine polymer and inorganic polyoxometalate. The detail investigation against Shigella flexneri 2a cell line demonstrates that the collaborative mechanism of the ternary hybrid composite enhances the bactericidal activity in comparison to only polyoxometalate and polymer stabilized silver nanoparticle with an altered mechanism of action which is established via detailed biological analysis.

Effect of “corona-core” structuring of poly(1-vinyl-1,2,4-triazole)–poly(acrylic acid)-Ag(I) interpolymer complexes on the radiation-induced preparation and stability of silver nanoparticles

Interpolymer complexes (IPC) of water-soluble polymers can be promising matrices for the synthesis of metal colloids. In this work, silver nanoparticles were obtained via radiation-induced reduction (under X-ray irradiation) of complexes based on poly (1-vinyl-1,2,4-triazole) (PVT) and poly (acrylic acid) (PAA) containing Ag+ ions. Particular attention was paid to the role of the supramolecular structure in the formation of nanoparticles. Combined dynamic light scattering and electrophoretic mobility measurements have revealed that, in pH range 5.5–7, micro-scale aggregates of the initial PVT-PAA-Ag(I) IPC transform into nano-sized particles consisting of a PVT-Ag(I) core electrostatically stabilized by PAA loops and tails forming a corona. It was explicitly demonstrated for the first time that such transformation of IPC aggregates can significantly enhance the efficiency of AgNPs formation. In particular, using UV-VIS spectroscopy and transmission electron microscopy, we have shown that at pH 7.0 the core of the “corona-like” form of the PVT-PAA-Ag(I) complex ensures the radiation-induced generation of AgNPs with a narrow size distribution due to the strong affinity of triazole groups to the metal surface. At the same time, the localization of the excessive negatively charged carboxylate groups in the outer part of the complex provides a long-term colloidal stability of the prepared AgNPs.

Biochemical properties of novel Carbon nanodot-stabilized silver nanoparticles enriched calcium hydroxide endodontic sealer.

Calcium Hydroxide-based endodontic sealer loaded with antimicrobial agents have been commonly employed in conventional root canal treatment. These sealers are not effective against E. faecalis due to the persistent nature of this bacterium and its ability to evade the antibacterial action of calcium hydroxide. Therefore, endodontic sealer containing Carbon nanodots stabilized silver nanoparticles (CD-AgNPs) was proposed to combat E. faecalis. The therapeutic effect of CD-AgNPs was investigated and a new cytocompatible Calcium Hydroxide-based endodontic sealer enriched with CD-AgNPs was synthesized that exhibited a steady release of Ag+ ions and lower water solubility at 24 hours, and enhanced antibacterial potential against E. faecalis. CD-AgNPs was synthesized and characterized morphologically and compositionally by Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy (FTIR), and UV-Vis Spectroscopy, followed by optimization via minimum inhibitory concentration (MIC) determination against E. faecalis by broth microdilution technique and Cytotoxicity analysis against NIH3T3 cell lines via Alamar Blue assay. Calcium hydroxide in distilled water was taken as control (C), Calcium hydroxide with to CD-AgNPs (5mg/ml and 10mg/ml) yielded novel endodontic sealers (E1 and E2). Morphological and chemical analysis of the novel sealers were done by SEM and FTIR; followed by in vitro assessment for antibacterial potential against E. faecalis via agar disc diffusion method, release of Ag+ ions for 21 days by Atomic Absorption Spectrophotometry and water solubility by weight change for 21 days. CD-AgNPs were 15-20 nm spherical-shaped particles in uniformly distributed clusters and revealed presence of constituent elements in nano-assembly. FTIR spectra revealed absorption peaks that correspond to various functional groups. UV-Vis absorption spectra showed prominent peaks that correspond to Carbon nanodots and Silver nanoparticles. CD-AgNPs exhibited MIC value of 5mg/ml and cytocompatibility of 84.47% with NIH3T3 cell lines. Novel endodontic sealer cut-discs revealed irregular, hexagonal particles (100-120 nm) with aggregation and rough structure with the presence of constituent elements. FTIR spectra of novel endodontic sealers revealed absorption peaks that correspond to various functional groups. Novel endodontic sealers exhibited enhanced antibacterial potential where E-2 showed greatest inhibition zone against E. faecalis (6.3±2 mm), a steady but highest release of Ag+ ions was exhibited by E-1 (0.043±0.0001 mg/mL) and showed water solubility of <3% at 24 hours where E-2 showed minimal weight loss at all time intervals. Novel endodontic sealers were cytocompatible and showed enhanced antibacterial potential against E. faecalis, however, E2 outperformed in this study in all aspects.

Formation, structure, and morphology of nanofiber mat on the base sodium‐carboxymethylcellulose/polyvinyl‐alcohol/silver nanoparticles composite

AbstractStable silver nanoparticles were synthesized in solutions containing sodium‐carboxymethylcellulose and polyvinyl alcohol, and their structure, morphology, and physicochemical properties were studied. The morphology and diameter sizes of the nanofibers of carboxymethylcellulose/polyvinyl alcohol containing silver nanoparticles were investigated using atomic force microscopy and scanning electron microscopy. The investigations showed that nanofibers with diameter sizes ranging from 50 to 130 nm were obtained from the carboxymethylcellulose/polyvinyl alcohol/silver nanoparticles solution. The size and form of silver nanoparticles formed within the solution of carboxymethylcellulose/polyvinyl alcohol based on nanofiber were determined by X‐ray diffraction (XRD), UV–visible (UV–VIS) spectroscopy, and dynamic light scattering (DLS) investigations, revealing nanoparticles with diameters ranging from 5 to 26 nm. The nanofiber mat containing silver nanoparticles exhibited significant antimicrobial activity against both Staphylococcus epidermidis and Candida albicans. The nanofiber mat containing stable silver nanoparticles could be utilized as an antimicrobial facemask for air filtration and for the treatment of burn wounds.

Eco-friendly synthesis of N- cholyl mercapto histidine capped silver nanoparticles and its sensing of mercury (II) ions and photo catalytic degradation of methyl orange

In this report, we have developed highly water soluble and stable silver nanoparticles (Ag NPs) utilizing N-Cholyl Mercapto Histidine (NCMH) as a reducing and stabilizing agent with near the primary critical micellar concentration (CMC) under ambient sunlight irradiation. Moreover, The NCMH was firstly synthesized by demonstrating the reaction between cholic acid and 2- Mercapto Histidine through a simple acid amine coupling approach. The primary and secondary CMC of NCMH surfactant was measured by pyrene (1 × 10−6 M) as a fluorescent probe, and values were found to be 3.2 and 13.1 mM respectively. The synthesized Ag NPs showed at neutral pH and highly stable for more than one year without any noticeable aggregation. The TEM analysis displays the synthesized Ag NPs having a spherical shape and average size of 9.6 ± 0.5 nm. The synthesis of stabilized Ag NPs was used for ultra-sensitive and selective detection of Hg2+ ions in aqueous medium were monitored by Uv–visible spectrometer and naked eyes with a lowest limit of detection (LOD) 7 nM. The photo-catalytic degradation of methyl orange (MO) by utilizing Ag NPs as nano-catalyst exhibits a potential degradation within a study period of 180 min. Concluding that, facile and cost effective green synthesis of NCMH capped Ag NPs possess excellent reducing ability towards the selective detection of Hg2+ ions along with photo-catalytic degradation of MO dye. These true findings detached an innovative pathway of Ag NPs towards the reactivity against the catalytic activity of dye degradation and selective sensing of Hg2+ ions. Thus it paves the way for extensive range of novel potential applications of Ag NPs in various environment friendly approaches of sensitive and analytical protocol in the future.

Stable silver nanoparticles synthesis using Tabebuia aurea leaf extract for efficient water treatment: A sustainable approach to environmental remediation

Noble metal nanoparticles have garnered significant attention owing to their extensive utility across various domains. Among them, silver nanoparticles (SNP) deliver solutions to various environmental problems in the area of water treatment. SNP are conventionally fabricated using chemical methods with toxic chemicals. In this work, we used leaf extract of Tabebuia aurea to rapidly synthesize stable silver nanoparticles (TA-SNP). The analysis of the UV–vis spectrum revealed surface plasmon resonance at 438 nm which confirmed the formation of SNP. The SEM image showed the nanosized and spherical morphology of the TA-SNP with a mean size of 48.68 nm. XRD pattern of nanoparticles pertaining to (101) plane, ascertained the fcc crystal arrangement with 19.36 nm as crystallite diameter. DLS confirmed the colloidal stability with a zeta potential of −26.7 mV. The FTIR studies suggest that the presence of various functional moieties of the leaf extract is accountable for the formation and capping of nanoparticle synthesis. The efficiency of TA-SNP as a potential catalyst in the reduction of the Congo Red and Acid Blue 113 dye with NaBH4 was demonstrated with first-order kinetic constants of 0.2723 and 0.1335 min –1 respectively. Hence, the environmentally friendly and cost-effective synthesis method used for SNP in the present study holds promise for developing nanocatalysts aimed at effectively removing diverse dyes from wastewater, thereby contributing to environmental remediation.

Photocatalysis-enhanced synthesis and stabilization of silver nanoparticles by methanol-based phytochemicals extract of Trigonella foenum-graecum seeds

Trigonella foenum-graecum is an economically important plant that has significant nutraceutical properties. Various parts of the plant have previously been reported to synthesize metal nanoparticles. However, the seeds of the plant have limited potential to synthesize metal nanoparticles. Green synthesis of silver nanoparticles requires phytochemicals as reducing and metal chelating agents, in addition to the stabilizing agents that play critical role in nanoparticles stabilization. The quantitative analysis of the methanol extract of the seeds suggest that the extract has significant antioxidant activity and reducing potential which is comparable to that of ascorbic acid. Likewise, GCMS data of the extract identified several phytochemical components that have nanoparticles stabilizing potential. Evidently, the extract indeed synthesized silver nanoparticles in dark, albeit in very low quantity. This limitation of low quantity of nanoparticles synthesis was overcome by photocatalysis. The rate of nanoparticles synthesis increased significantly with increase in the intensity of the white light-emitting diode (LED) light. Furthermore, the photocatalytic effect of the white light also has significant impact on the physicochemical characterisation of the nanoparticles. Particle size, nanoparticles yield and elemental analysis demonstrated that the 2000 lumens white LED light is optimum for photocatalysis as compared to the 250 lumens and 825 lumens light. However, the stability of nanoparticles is not influenced by photoirradiation, and is rather controlled by the phytochemical composition of the extract. Methanol extract of the seeds significantly enhanced the stability of the silver nanoparticles irrespective of the light intensities used for photocatalysis.

Fabrication of Silver Nanoparticles Using Acalypha paniculata Extract, AI-Based Interaction Analysis and Its Activity Explication

This study showcases eco-friendly silver nanoparticle synthesis using Acalypha paniculata herb and its biological activity. Artificial Intelligence (AI) tools are used to analyze the interaction between phytoconstituent and silver ion to find the capping and nanoparticle fabricating phytoconstituents. Ethanolic extract was added to silver nitrate solution and irradiated under sunlight until the formation of silver nanoparticles. These particles were sedimented, characterised by spectral technique and biological activity was measured. Finally, a Computational simulation algorithm was used to visualize the interactions of phytoconstituent and silver nanoparticles. Ultra Violet (UV)-visible spectrum revealed a visible peak at 420nm in the brownish solution, Dynamic Light Scattering (DLS) size of 54.7nm, spherical crystalline morphology of the nanoparticle by Transmission Electron Microscope (TEM) and X-Ray Diffraction (XRD) analysis. The synthesized silver nanoparticle antagonised Escherichia coli, and Bacillus cereus and showed the Minimum Inhibitory Concentration (MIC) of 65 µg/mL, and 78 µg/mL respectively and Minimum Bacterial Concentration (MBC) of 52.5 µg/mL for B.cereus and 61.5µg/mL for E.coli. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals IC50 was found to be 97.414 µg/mL and it revealed the dose-dependent antioxidant activity of phyto-capped silver particles. The cytotoxicity of fabricated nanoparticles was studied on Vero cells and the results indicate that IC50 of 47.28 µg/mL. Furthermore, an AI-based study concludes that Alloaromadendrene adsorbed highly by the Silver (Ag) ion compared to the nitrate with an affinity of -30.6755 kcal/mol. This research introduces an innovative, cost-effective method for stable Acalypha paniculata Silver Nanoparticles (AP-AgNPs) fabrication, crucial for diverse biomedical uses.