Size Of AgNPs Research Articles

Synthesis of pure alginate-nano silver biocomposites via solution plasma process and their potentials as antimicrobial agents

In this study, pure and safe biocomposites were synthesized via solution plasma process (SPP) that employed Ag electrodes as the precursor for AgNPs, which replaced AgNO3 and tungsten electrodes studied previously. In order to synthesize pure and medical grade biocomposites with AgNPs, Ag electrode was used. Plasma was discharged in 0.5% (w/v) or 0.75% (w/v) alginate solution at 800 voltages, 30 kHz for 2–7 min using a unipolar power supply and a reactor equipped with Ag electrodes. UV–Vis spectroscopy of the biocomposites showed a unique peak at 405.5 - 411 nm, indicating the synthesis of AgNPs. FTIR analysis indicated no change in the chemical bonds of alginate during the plasma discharge. SEM/TEM analyses showed that the biocomposites had micro-porous and micro-fibril structures with spherical AgNPs well dispersed in the alginate matrix. The average sizes of AgNPs were 12.5 ± 9.9 - 14.5 ± 6.9 nm and the size range of 2–41 nm. Dispersion stability of the biocomposites (0.75%, w/v, alginate) was excellent with zeta-potential values of −72.86 to −75.78 mV. Among them, 0.75% (w/v) alginate/AgNP discharged for 5 min showed the highest antimicrobial activity. The MICs of AgNPs in the biocomposites were 12.5–25.0 μg mL-1 for Gram-negative bacteria (E.coli, P.aeruginosa, V.vulnificus), 30.0–35.0 μg mL-1 for Gram-positive bacteria (S.aureus, B.cereus), and 265.0 μg mL-1 for C. albicans. The biocomposite did not exhibited significant toxicity against the HEK293 cells up to 300 μg/ml with LC50 of 419.2 ± 29.9 μg mL-1. Therefore, SPP using Ag electrodes is an improved and efficient way to produce pure and safe antimicrobial agents.

Exploring the antibacterial effects of Ocimum sanctum (O. sanctum) silver nanoparticles

The current study was undertaken to provide sustainable solutions to Erythromycin-resistant bacterial strains. Silver nanoparticles were produced using an environmentally friendly green synthesis process using Ocimum sanctum leaf extract. The synthesized Ocimum sanctum leaf extract silver nanoparticles were then examined using a variety of methods. In the UV-Vis spectrophotometer, the peak was observed at 398nm. Scanning electron microscopy (SEM) revealed the size of the nanoparticles to be between 24-44nm. The crystalline size of AgNPs was determined to be 12.02nm by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy revealed the presence of functional groups like alcohols, phenols and carbonyl groups which provide better interaction and stability of the nanoparticles. Bioactive compounds of Ocimum sanctum leaves were found to be effective against both Gram-positive and Gram-negative bacterial strains as nanoparticles which is evident by having no inhibition against Bacillus Subtilis and E. coli in lower concentrations of 30μl and 50μl. On the other hand, Ocimum sanctum leaf extract AgNPs had a positive dose-dependent inhibition against all the strains. The Ocimum sanctum silver nanoparticles were effective against E. coli (Gram-negative), Staphylococcus aureus (1.9cm), Streptococcus mutans (1.7cm) and Bacillus Subtilis (Gram-positive). Thus, Ocimum sanctum Silver Nanoparticle-based drug delivery has proven to be an effective anti-bacterial treatment worth exploring specifically against Erythromycin-resistant strains.

Red light enhances the antibacterial properties, biofabrication, and stability of Fagonia indica callus-based silver nanoparticles.

Plant-based nanoparticles can be tuned through the frequency of light for efficient synthesis, structural properties, and antibacterial applications. This research assessed the effect of material type (callus and whole-plant extract) and the interaction with a specific range of light wavelength on AgNP synthesis. All types of AgNPs were characterized by their size, shape, associated functional groups, and surface charge. Interestingly, the size of red light and callus-based AgNPs (RC-AgNPs) was smaller (6.32 nm) compared to 14.59 nm for Ultraviolet light and callus-based AgNPs (UV-C-AgNPs). Zeta potential analysis showed that RC-AgNPs had higher stability (-29.2 mV) compared to UV-C-AgNPs (-16.7 mV). Similarly, red light-based AgNPs had higher Oxidation reduction potential in both whole-plant-based and callus-based AgNPs, indicating a more oxidizing nature compared to those synthesized under UV light. This was confirmed by the lower total phenolic and flavonoid content associated with them and their lower antioxidant activity. The higher antibacterial activities and lower minimum inhibitory concentrations of red light-based AgNPs against highly resistant pathogenic bacteria demonstrated the role of red light in enhancing antibacterial activity. These results indicate that AgNPs synthesized in red light and callus extract are more active compared to those synthesized under other wavelengths and/or in whole-plant extracts.

Revolutionizing Nanotechnology with Filago desertorum Extracts: Biogenic Synthesis of Silver Nanoparticles Exhibiting Potent Antioxidant and Antibacterial Activities.

In this study, we described the environmentally friendly biosynthesis of silver nanoparticles (AgNPs) utilizing ethanolic extract of Filago desertorum (F. desertorum) as a capping and reducing agent. We also looked at the antioxidant and antibacterial capacities of AgNPs. In order to determine the size, shape, and crystallinity of the created AgNPs, the current project was designed to produce AgNPs utilizing the crude extract of the F. desertorum. The effectiveness of the project was evaluated by UV-visible spectrophotometry, Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray diffraction. AgNPs are monodispersed and spherical and have 50 nm average particle diameters, as determined using Image J software calculations and SEM observation. Four significant peaks from an XRD study, located at 38.46, 44.63, 64.81, and 77.74 nm, were used to calculate the average crystalline size of AgNPs which was reported to be 15 nm. In the crude extract of F. desertorum, it is possible to see the functional group peaks of a number of substances that are essential for bioreduction and the stability of the AgNPs. Antibacterial and antioxidant properties of AgNPs in vitro (DPPH, ABTS, H2O2, phosphomolybdenum, and ferric reducing power) were examined using conventional methods. The AgNPs showed maximum DPPH (72.51% with IC50 = 144.61 μg/mL), ABTS (75.24% with IC50 = 131.21 μg/mL), hydrogen peroxide (73.33% with IC50 = 115.05 μg/mL), phosphomolybdenum activity (73.43% with IC50 = 75.25 μg/mL), and observing reducing power (0.25) at a concentration of 250 g/mL. Inhibition by the AgNPs against the bacterial strain Staphylococcus aureus was greatest (12 mm). According to the current findings, AgNPs produced by F. desertorum have the highest potential for free radical scavenging and antibacterial activity, which can result in antioxidant and antibiotic agents.

Green synthesis of silver nanoparticles using Sorghum bicolor var. technicum seed extract, their characterisation and investigation of biological activities

AbstractSynthesis of nanoparticles can be long and costly processes using physical and chemical methods. Biological synthesis of nanoparticles is known to be cheaper and easier than other methods. In this study, silver nanoparticles (AgNP) were obtained by biological synthesis, also known as green synthesis, using Sorghum bicolor var. technicum (Körn) Stapf ex Holland seed extract, popularly known as sorghum. AgNPs were characterised by SEM, EDS, TEM, FT-IR, and UV-Vis Spectroscopy. SEM images confirmed that the shape of AgNPs was spherical. TEM analysis showed that the average sizes of AgNPs ranged from 51 to 56 nm. EDS analysis confirmed the presence of AgNPs by detecting a silver ion peak at 3 KeV. UV-Vis spectroscopy analyses indicated that the brown-burgundy colour of AgNPs exhibited maximum absorbance at 450 nm. The biological activities of the extract and AgNPs were investigated through antimicrobial, antibiofilm, antioxidant, mutagenic, and DNA cleavage activity analyses. The extract exhibited the highest MIC value against Gram-positive bacterium Bacillus subtilis (0.62 μg mL−1), whereas AgNPs demonstrated the highest antimicrobial activity specifically against Gram-negative bacterium Escherichia coli (0.31 μg mL−1). The antibiofilm results revealed that the extract displayed the highest percentage of biofilm inhibition against B. subtilis, while AgNPs exhibited notable efficacy against both Candida albicans yeast and Pseudomonas aeruginosa bacterium. The antioxidant activities were evaluated using DPPH• and ABTS•+ methods, and it was determined that both samples had high antioxidant activity. Mutagenicity of the extract and AgNPs were evaluated by the Ames/Salmonella test using two strains of Salmonella typhimurium (TA98 and TA100). The mutagenic activity of the extract increased depending on the concentration for both strains, while AgNP did not show mutagenicity at any concentration. The agarose gel electrophoresis method showed that the extract and AgNPs cleaved DNA in the presence of an oxidising agent.

Green Synthesis of Silver Nanoparticles of Vernonia cinerea Leaf Extract and their In vitro Cytotoxicity Activity against Neuroblastoma SHSY-5Y Cell Lines, Antimicrobial and Antioxidant Studies.

Green syntheses of silver nanoparticles using plant extracts have potential anti- cancer, antimicrobial, and antioxidant properties, among other aspects. The aim of the present patent study was to synthesize silver nanoparticles (AgNPs) using Vernonia cinerea plant extract. The AgNPs were successfully prepared and characterized using UV-Vis Spectrophotometer, particle size, Zeta potential, Transmission electron microscopy (TEM), Energy-dispersive x-ray analysis (EDAX), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectrometry. The in vitro cytotoxicity study was performed using neuroblastoma SHSY-5Y cell lines. Moreover, antimicrobial and antioxidant activity studies were also performed for AgNPs. The size of AgNPs determined through the dynamic light scattering (DLS) technique was 49.5 nm and the zeta potential was -36.8 mV. The synthesized AgNPs were checked using UV-Visible spectroscopy at ƛmax 439 nm. The color was changed from green to dark brown, indicating the formation of AgNPs. The TEM study revealed that the nanoparticles were spherical in shape. The XRD pattern of AgNPs produced in this experiment was apparently crystalline. The results of FTIR study revealed that the majority of the obtained peaks correspond to the polyphenols, triterpenoids, and alkaloids which were abundant in the corresponding to the V. cinerea leaf extract and support to the formation of AgNPs. The cytotoxicity effect of the V. cinerea plant extract and biosynthesized AgNPs was found to be dosedependent. From the results of antimicrobial studies, it was reported that the gram negative bacteria were found to be more susceptible compared to the gram positive bacteria. Moreover, the results of antioxidant study revealed that the AgNPs showed good antioxidant activity (77.21%) in comparison to the V. cinerea plant extract (56.13%). Based on the results, it could be concluded that the green synthesized silver nanoparticles showed promising anticancer, antioxidant, and anti-bacterial activities as compared to the plain V. cineria plant extract.

Aqueous extraction of red seaweed bioactive compounds and synthesis of silver nanoparticles for agriculture applications

In this study, an aqueous extract of Gracilaria crassa and Grateloupia lithophila was used for the green synthesis of silver nanoparticles (AgNPs) to control plant disease and support plant growth. The synthesised AgNPs were characterised using a UV–visible spectrophotometer, FTIR, XRD, SEM, EDAX, TEM and DLS analysis. The TEM image revealed that synthesised nanoparticles with average size of 51 nm and 20 nm were observed in G. crassa and Grateloupia lithophila extract, respectively. The green synthesised AgNPs exhibited a strong antibacterial activity against Xanthomonas axonopodis pv. citri and Xanthomonas oryzae pv. oryzae, and investigated the effect of biogenic AgNPs on seed germination and seedling growth of rice plants (Oryzae sativa L). Both the sizes (51 and 20 nm) of AgNPs treatments (50 μg/ml conc.) resulted in the highest seed germination rate (98 and 99%), longer roots (17.51 ± 0.50 and 17.68 ± 0.10 cm) and shoot lengths (5.68 ± 0.12 and 6.18 ± 0.10 cm), and produced higher amount of fresh (8.98 ± 0.34 and 9.00 ± 0.14 mg) and dry (3.68 ± 0.05 and 3.80 ± 0.12 mg) biomass weights. On the other hand, rice seedlings treated with both sizes of AgNPs, particularly at 100 μg/ml concentration, responded with a lower rate of seed germination, shorter root and shoot length and a lower amount of fresh and dry biomass weight was observed. The nanocomposites synthesised from Grateloupia lithophila (20 nm) were more effective in seed germination and seedling growth than G. crassa (51 nm) nanocomposites. In this study, one-step synthesised AgNPs from red seaweeds extracts controlled the bacterial pathogens causing disease in rice and promoted the growth of the plant.

A COMET ASSAY FOR CANDIDA GLABRATA INFECTION AND TREATMENT BY PENICILLIUM CHRYSOGENUM - DERIVED AgNPs

The colonies of C. glabrata were described, which morphology of isolated on sabouraud dextrose agar with chloramphenicol. Biosynthesis of nanoparticles is of great importance since they are highly involved in various medical and biological applications. The current study aims to produce Penicillium chrysogenum - derived AgNPs to be used to treat Candida glabrata. Nanoparticles were formed, the results of which was observed through UV-visible spectrophotometry. Therefore, the surface morphology and particles size of AgNPs were assessed using the scanning electron microscope (SEM). The atomic force microscopy (AFM) confirmed that the average diameter of AgNPs was 18 nm which is appropriate to be used to deliver Penicillium chrysogenum to the Candida infected cells. The antifungal activity of AgNPs against C. glabrata was investigated in the serum of 15 mice. The mice were divided into four groups was examined after 21 days. A comet assay described procedure that sensitive measurement and permits reproducible of DNA repair and DNA damage using C. glabrara infection and treatment by Penicillium chrysogenum - derived AgNPs. This combination of assay with affected C. glabrara in DNA repaired and the extensive range of obtainable fungal molecular biology apparatuses can donate to light important devices of genome.

Silver and gold nanoparticles: Eco-friendly synthesis, antibiofilm, antiviral, and anticancer bioactivities

For the first time in this study, silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were green synthesized by the cost-effective and eco-friendly procedure using Cotton seed meal and Fodder yeast extracts. The biosynthesized NPs were characterized by UV–Vis spectroscopy, dynamic light scattering analysis (DLS), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and fourier-transform infrared (FTIR) spectroscopy. Furthermore, the biosynthesized NPs were tested in vitro against biofilm formation by some pathogenic negative bacteria (Escherichia coli, Proteus mirabilis, Klebsiella sp., Salmonella sp., and Pseudomonas aeruginosa) and negative bacteria (staphylococcus aureus) as well as against human denovirus serotype 5 (HAdV-5) and anticancer activity using HepG2 hepatocarcinoma cells. UV–Vis absorption spectra of reaction mixture of AgNPs and AuNPs exhibited maximum absorbance at 440 nm and 540 nm, respectively. This finding was confirmed by DLS measurements that the highest intensity of the AgNPs and AuNPs were 84 nm and 73.9 nm, respectively. FTIR measurements identified some functional groups detected in Cotton seed meal and Fodder yeast extracts that could be responsible for reduction of silver and gold ions to metallic silver and gold. The morphologies and particle size of AgNPs and AuNPs were confirmed by the TEM and SAED pattern analysis. Biosynthesized AgNPs and AuNPs showed good inhibitory effects against biofilms produced by Escherichia coli, Proteus mirabilis, Klebsiella sp., Salmonella sp., Pseudomonas aeruginosa, and Staphylococcus aureus. In addition, they showed anticancer activities against hepatocellular carcinoma (HepG-2) and antiviral activity against human adenovirus serotype 5 infection in vitro. Finally, the results of this study is expected to be extremely helpful to nano-biotechnology, pharmaceutical, and food packing applications through developing antimicrobial and/or an anticancer drugs from ecofriendly and inexpensive nanoparticles with multi-potentiality.

Fabrication, surface characterization and electrical properties of hydrogen-irradiated nanocomposite materials

Flexible poly(vinyl alcohol) (PVA)/polyaniline (PANI)/silver (Ag) nanocomposites consisting of PANI and silver nanoparticles (AgNPs) with PVA were successfully fabricated using the casting method for application in energy-storage devices. The surface characteristics of the composite films were analyzed using X-ray diffraction, differential scanning calorimetry and Fourier transform infrared spectroscopy techniques. The estimated crystallite size of AgNPs was 11.7 nm, which increased to 15.3 nm by increasing silver from 2 to 4%. In addition, the morphology of the films was investigated utilizing scanning electron microscopy. The conductivity σ DC improved from 4.8 × 10−11 S/cm for PVA to 1.3 × 10−10 S/cm for PVA/PANI and to 1.2 × 10−9 S/cm for PVA/PANI/silver. Furthermore, with an increasing temperature value, the electrical resistance was reduced. Moreover, the activation energy was modified with the addition of PANI and silver into the PVA matrix. PVA/PANI/silver was irradiated with hydrogen fluences of 0.4 × 1018, 0.8 × 1018 and 1.2 × 1018 ions/cm2. σ AC was enhanced from 2.67 × 10−9 S/cm for PVA/PANI/silver to 2.02 × 10−8 S/cm for 0.4 × 1018 ions/cm2 and to 3.95 × 10−6 S/cm for 1.2 × 1018 ions/cm2. Moreover, the dielectric constant increased from 0.43 for PVA/PANI/silver to 0.56, 1.23 and 4.18 with exposure to 0.4 × 1018, 0.8 × 1018 and 1.2 × 1018 ions/cm2, respectively. The results showed modifications in the electrical characteristics of the irradiated composites, which opened the way for applying these samples in a wide range of dielectric applications.

Synthesis, optimization and characterization of Silver nanoparticles using aqueous seed extract of Trigonella foenum‐graceum L. for catalytic reduction of p‐nitrophenol

AbstractThe present study was focused on green synthesis of Silver nanoparticles (AgNPs) using Trigonella foenum‐graceum L. seed extract belonging to specific variety HM (Hisar Mukta) 425, optimizing the different experimental conditions required for the formation and stability of AgNPs. UV‐Vis spectroscopy, Particle Size Analyzer (PSA), Field Emission Scanning Electron Microscopy (FESEM), High Resolution Transmission Electron Microscopy (HRTEM), X‐ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) were used to characterise the synthesised AgNPs. The average size of AgNPs was found to be 22 nm and were spherical in shape. Additionally, the United States Environmental Protection Agency (USEPA) has listed nitrophenols as a priority pollutant, and biosynthesized AgNPs can catalytically convert them into less harmful aminophenols. One example of a reaction where AgNPs are used as a catalyst is the conversion of p‐nitrophenol to p‐aminophenol, which acts as a bridge for many analgesics and antipyretic medications. Hence, the study is anticipated to have a significant impact on the pharmaceutical, cosmetic, and food industries.

Mapping the Progress in Surface Plasmon Resonance Analysis of Phytogenic Silver Nanoparticles with Colorimetric Sensing Applications.

Nanotechnology is gaining enormous attention as the most dynamic research area in science and technology. It involves the synthesis and applications of nanomaterials in diverse fields including medical, agriculture, textiles, food technology, cosmetics, aerospace, electronics, etc. Silver nanoparticles (AgNPs) have been extensively used in such applications due to their excellent physicochemical, antibacterial, and biological properties. The use of plant extract as a biological reactor is one of the most promising solutions for the synthesis of AgNPs because this process overcomes the drawbacks of physical and chemical methods. This review article summarizes the plant-mediated synthesis process, the probable reaction mechanism, and the colorimetric sensing applications of AgNPs. Plant-mediated synthesis parameters largely affect the surface plasmon resonance (SPR) characteristic due to the changes in the size and shape of AgNPs. These changes in the size and shape of plant-mediated AgNPs are elaborately discussed here by analyzing the surface plasmon resonance characteristics. Furthermore, this article also highlights the promising applications of plant-mediated AgNPs in sensing applications regarding the detection of mercury, hydrogen peroxide, lead, and glucose. Finally, it describes the future perspective of plant-mediated AgNPs for the development of green chemistry.

Nanosilver-doped carbon quantum dots for industrialization of efficacious textiles with superior UV-resistance and antimicrobial performance

Numerous researches were interestingly considered with investigation of unique strategies for industrialization of efficacious textiles to find wide-scaled applicability in different purposes. The demonstrated approach represents unique strategy for manufacturing of fluorescent/UV-resistant/microbicide cotton via exploitation of silver nanoparticles (AgNPs), carbon quantum dots (CQDs) and silver nanoparticles-doped carbon quantum dots (AgNPs-CQDs) to be applicable as efficacious textiles. Whereas, both CQDs and AgNPs were formerly clustered from alginate biopolymer. Topographical features and particle size of AgNPs (7.5 ± 2.6 nm), CQDs (4.9 ± 1.7 nm) & AgNPs-CQDs (4.0 ± 1.4 nm) were investigated via microscopic images and Zetasizer data. Spectral mapping data for the photoluminescent emission showed that, AgNPs, CQDs & AgNPs-CQDs were exhibited with two intense peaks at 370 nm & 490 nm. Cotton fabrics were sequentially treated with CQDs, Ag-CQDs & AgNPs-CQDs to prepare CQDs@Cotton, Ag-CQDs@Cotton and AgNPs-CQDs@Cotton, respectively. Thermal stability, colorimetric properties/color strength, UV-resistance and antimicrobial potentiality were studied for all the prepared samples. AgNPs-CQDs@Cotton exhibited excellent UV-resistance (UPF, 43.4) and antimicrobial activity, whereas the diameter of inhibition zone was estimated for its affinity against S. aureus, E. coli and C. albicans, to be 14 mm, 18 mm and 16 mm, respectively.

Characterizing the Size Distribution of Silver Nanoparticles Biofabricated Using Calotropis gigantea from Geothermal Zone

This research aims to synthesize silver nanoparticles (AgNPs) using an aqueous leaf extract of Calotropis gigantea obtained from the geothermal manifestation Ie Seu-Um, Aceh Besar, Aceh Province, Indonesia. The C. gigantea leaf extract was mixed with AgNO3 solutions at concentrations of 2, 5, and 9 mM, respectively. The mixture was stirred at 80 rpm by a magnetic stirrer for 48 hours in the dark. The change in solution color indicated the reduction of Ag+ to Ag0. The resulting AgNPs synthesized using C. gigantea leaf extract (AgNPs-LCg) exhibited cloudy grey, reddish dark brown, and light brown colors when synthesized with AgNO3 concentrations of 2, 5, and 9 mM, respectively. The particle sizes of AgNPs-LCg had maximum frequencies at 246.98 nm (synthesized using AgNO3 2 mM), 93.02 nm (synthesized using AgNO3 5 mM), and 171.25 nm (synthesized using AgNO3 9 mM). The zeta potential values of AgNPs-LCg using 2, 5, and 9 mM AgNO3 were -41.9, -40.1, and -31.4 mV, respectively. Based on the solution color, nanoparticle size, and stability value of AgNPs, it can be concluded that the use of AgNO3 at 5 mM is optimal for the green synthesis process of AgNPs-LCg.

Expeditious and Eco-friendly fabrication of Graphene-Ag nanocomposite for methyl paraben sensing

The synthesis of graphene-based nanocomposites using wet chemical techniques entails a number of time-consuming and laborious synthesis stages in addition to the use of potentially dangerous substances. The present article provides a novel approach to green and in-situ synthesis that employs no hazardous chemicals and synthesizes graphene and silver nanoparticles (Ag NPs) nanocomposite from the tea tree oil and silver nitrate (AgNO3) vapours. The synthesis happens in a matter of seconds in microwave plasma at ambient conditions. Images from the scanning and transmission electron microscopy revealed that graphene nanosheets act as the most favoured sites for the Ag NPs to anchor and form a nanocomposite. The investigations revealed a correlation between the concentration of AgNO3 in the precursor and the size and aggregation of Ag NPs. The results of X-ray photoelectron spectroscopy demonstrated a negative shifting of the Ag-doublet, which suggested a strong interaction between Ag NPs and graphene. Additionally, the graphene-Ag nanocomposite drop-casted on screen-printed electrode demonstrated good electrochemical sensing capability for methyl paraben, with a superior linear range of 20 to 260 µM and a commendable limit of detection of 2.5 µM.

A rapid, high-yield and bioinspired synthesis of colloidal silver nanoparticles using Glycyrrhiza glabra root extract and assessment of antibacterial and phytostimulatory activity.

Silver nanoparticles (AgNPs) have emerged as highly effective antimicrobial agents against multidrug-resistant (MDR) pathogens. This study aims to employ green chemistry principles for AgNP synthesis involving phytochemical-rich extract from Glycyrrhiza glabra roots. The approach highlights using renewable feedstocks, safer chemicals, minimum byproducts, and process scale-up. The synthesis of AgNPs was assessed using a surface plasmon resonance band at 420 nm, and structural properties were characterized using TEM, x-ray diffraction, Fourier-transform infrared spectroscopy, and X-ray photoelectron spectroscopy. This method enables the production of high-yield dispersions of AgNPs with desired physicochemical characteristics, including dark yellow solution, size (~20 nm), spherical to an oval shape, crystal structure, and stable colloidal properties. The antimicrobial activity of AgNPs was investigated against the MDR bacteria strains of gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli). This work reveals that the antimicrobial activity of AgNPs can be influenced by bacterial cell wall components. The results demonstrate the strong interaction between AgNPs and E. coli, exhibiting a dose-dependent antibacterial response. The green approach facilitated the safer, facile, and rapid synthesis of colloidal dispersions of AgNPs, providing a sustainable and promising alternative to conventional chemical and physical methods. Furthermore, the effect of AgNPs on various growth parameters, including seed germination, root and shoot elongation, and dry weight biomass, was assessed for mung bean seedlings. The results revealed phytostimulatory effects, suggesting the promising prospects of AgNPs in the nano-priming of agronomic seeds. RESEARCH HIGHLIGHTS: Glycyrrhiza glabra root extract enabled rapid, high-yield, and eco-friendly synthesis of silver nanoparticles (AgNPs). Spectrophotometric analysis examined the optical properties, scalability, and stability of AgNPs. Transmission electron microscopy provided insights into the size, shape, and dispersity of AgNPs. Scanning electron microscopy revealed significant damage to gram-negative bacterial cell morphology and membrane integrity. AgNPs were found to enhance seed germination, seedling growth, and biomass yield of Vigna radiata.

Colorimetric and surface-enhanced Raman scattering method for vanillin detection based on two types of reduced silver nanoparticles

It’s the first time we found that vanillin and 3,3′,5,5′-tetramethylbenzidine (TMB) can reduce Tollens’ reagent to different types of Ag nanoparticles (Ag NPs) because of their different reducibility. Vanillin reduced the Tollens’ reagent to small size of Ag NPs (Ag45 NPs) which was colorless and has the maxmium absorption at 350 nm, while pink large Ag NPs (Ag100 NPs) with the maxmium absorption at 490 nm was reduced by TMB. Based on different types of AgNPs reduced by vanillin and TMB, dual-mode detection of vanillin by colorimetry and surface-enhanced Raman scattering (SERS) was designed. The solution changed from pink to colorless with the increasing concentration of vanillin (within 3 min). On the other hand, the reduced Ag45 NPs shows a high SERS enhancement factor, which can be applied for ultra-sensitive detection of vanillin in situ. The SERS had a low detection limit of 25.8 pM, which was 5-orders lower than the colorimetric method and most previously reported methods. Importantly, It avoids the additional procedures to prepare SERS-active substrates and can be used to discriminate vanillin from ethylvanillin, both of which are very difficult to be distinguished because of their much highly similar structure and property. Therefore, the visual, fast and high-sensitive dual-mode strategy has great potential in food safety assessment.

Biosynthesis and Characterization of Silver Nanoparticles Coated with Metabolites Extracted from Clerodendron phlomoides with Its Biochemical Studies in Liver Tissue

Silver nanoparticles (AgNPs) have been used as a potential nanomaterial-based drug delivery vehicle for liver cancer treatment, as it induces cell death and produces cytotoxicity against cancerous cells at a low concentration. The biosynthesis of green metallic nanoparticles uses secondary metabolites in plant extracts instead of toxic chemicals for a reduction-oxidation (redox) reaction. The biosynthesis of AgNPs with the aqueous extract of Clerodendron phlomoides was performed in this study. The phytochemical analysis of C. phlomoides extract using gas chromatography-mass spectrometry (GC-MS) confirmed the presence of redox metabolites. The peak at 489 nm in UV-visible spectra confirmed the formation of bioactive AgNPs reduced from silver nitrate solution, whereas the Fourier-transform infrared (FTIR) spectra indicated the bioactive molecules of plant extracts that are responsible for the formation. Scanning electron microscope (SEM) micrograph revealed the formation of spherical and ovoid structures of AgNPs, whereas transmission electron microscope (TEM) micrograph confirmed the size of AgNPs, which varies from 25 nm to 100 nm. X-ray diffraction (XRD) spectra showed the crystalline nature of AgNPs, and the size of crystallite was 4 nm, while dynamic light scattering (DLS) analysis confirmed the average particle size of AgNPs to be around 125 nm. In vivo studies showed that bioactive AgNPs have a significant anticancer potential against liver cancer, whereas biochemical studies of rats’ liver tissue samples confirmed that bioactive AgNPs produced a potential hepatoprotective effect against diethylnitrosamine-induced liver cancer.

Green synthesized nano-silver/cellulose aerogel as a robust active and recyclable catalyst towards nitrophenol hydrogenation

Water contamination by hazardous aromatic nitro compounds is a serious problem, and reduction in p-nitrophenol (PNP) by combining a catalyst and a reductant has been a topic of intense interest in recent years. Although several methods have been explored for generating effective metal nanoparticle composites, the nano-size makes it challenging to recover after wastewater treatment, thus restricting its practical use. Additionally, the previously described approaches had critical disadvantages, including high material synthesis costs and secondary environmental contamination. Herein, nontoxic and low-cost materials were employed. A novel green technique for the synthesis of silver nanoparticles (AgNPs) decorated on 3D cellulose aerogel (CA) derived from water hyacinth was demonstrated using an aqueous extract ofJasminum subtriplinerve Blumeleaves as a stabilising and reducing agent for high-performance towards PNP reduction in the presence of NaBH4 in an aqueous medium. The as-prepared composites were investigated by powder X-ray diffraction, scanning electron microscopy with energy-dispersive spectroscopy, high-resolution transmission electron microscopy, Fourier transform infrared spectroscopy and Raman spectroscopy. Batch experiments of PNP hydrogenation were conducted to evaluate the catalytic performance. At room temperature, the reaction could be completed in about 10 min using the 1.5Ag/CA2.0 catalyst, with the catalytic activity almost unchanged. Moreover, the structure has no apparent deterioration after five cycles. Strikingly, the 26.15 nm-average size of AgNPs with even distribution on CA correlates with the good kinetic characterisation/feature (k = 0.34 min−1). In particular, the reduction rates of the three isomers of nitrophenol were examined and found to follow the following order: PNP > o-nitrophenol (ONP) > m-nitrophenol (MNP). This study provides some valuable insights into developing easily separated robust green catalysts for heterogeneous catalytic reactions in the environmental remediation field.

Evaluation of cytotoxic activity against A549 human lung cancer cells using green synthesized N-Cholyl D-Penicillamine encapsulated silver and gold nanoparticles

Synthesis of noble metal nanoparticles (MNPs) using a biocompatible template provides a biologically safe, cost effective, and environment friendly approach in view of biomedical applications. In this manusctipt, synthesis of gold and silver nanoparticles (Au and Ag NPs) using N-cholyl D-penicilamine (NCPA) as an effective reducing and stabilizing agent at below the critical micellar concerntration (CMC) under sunlight exposure has been reported. The formation of NPs were optimized by changing the concentration of NCPA and pH of the medium. The synthesized Au and Ag NPs were characterized by UV-visible, FT-IR, DLS, Zeta potential and HR-TEM techniques. The average size of Au and Ag NPs were found to be 10.3 ± 0.4 and 9.1 ± 0.6 nm, respectively and exhibit stability for more than six month. The prepared NPs showed low toxicity on human erythrocytes (RBCs) even at their higher concentrations (120 μg/mL). The anticancer activity of NCPA capped NPs on A549 cells were investigated by cell viability assay, apoptosis analysis using MTT assay and Acridine Orange/Propidium Iodide (AO/PI) dual fluorescent staining asay. The results obtained from these studies suggest that the synthesized NPs showed potent cytotoxicity on A549 cells in a dose-dependent manner. Further, AgNPs showed better cytotoxicity as compared to AuNPs.