Synthesis Of AgNPs Research Articles

Excellent antibacterial and anti-inflammatory efficacy of amoxicillin by AgNPs and their conjugates synthesized using Micromeria biflora crude flavonoid extracts

Antibacterial resistance is considered to be one of the major causes for mortality in coming years. In recent years green nanotechnology played a key role in addressing this problem. Biocompatible metal nanoparticles have gained popularity owing to their excellent therapeutic effects and minimal side effects. MethodWe report the synthesis of AgNPs and their amoxicillin conjugates (Ag-amoxi) using Micromeria biflora crude flavonoid extracts. The physicochemical properties of the synthesized NPs and Ag-amoxi conjugates were systematically evaluated using scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD) analysis, Fourier transform infrared (FTIR), and UV–visible (UV–Vis) spectroscopic techniques. ResultsThe average sizes of AgNPs and Ag-amoxi conjugates were 45 and 62 nm, respectively. We have also explored the antibacterial, antioxidant, anti-inflammatory, and analgesic properties of the AgNPs and Ag-amoxi conjugates through in vivo and in vitro analysis. The Ag-amoxi conjugates showed better antibacterial potential against Streptococcus Pneumoniae (S.P), Staphylococcus aureus (S.A), Pseudomonas aeruginosa (P.A), and Methicillin resistance Staphylococcus aureus (MRSA) strain both the drug and AgNPs. Similarly, in vivo anti-inflammatory studies revealed that both Ag-amoxi (68 %) and AgNPs (64 %) had strong anti-inflammatory effects, with (***p < 0.001) significance at a dose of 10 mg kg−1 body weight as compared to standard, amoxicillin (45 %), and flavonoids extract (48 %) at a dose of 100 mg kg−1. The findings of the antinociceptive activities (writhing and hot plate tests) demonstrated that the Ag-amoxi conjugates produced fewer writhing (15 in 20 s) and a shorter latency time of 22 s as compared to vehicle-treated (tramadol) animals, amoxicillin, and P.E at much lower doses. In vitro antioxidant studies revealed that the Ag-amoxi conjugate has the potential to be used as an antioxidant with an IC50 value of 43.58, compared with AgNPs (46.34), amoxicillin (58.17), compared to the standard of ascorbic acid (34.14). ConclusionThese results reveals that these biologically inspired AgNPs and Ag-amoxi conjugate could be used to improve antibiotic efficiency and could play a critical role in addressing the multidrug resistance problem in coming years.

Effect of biosynthesized silver nanoparticle size on antibacterial and anti-biofilm activity against pathogenic multi-drug resistant bacteria

Ag NPs have garnered significant attention in the field of biomedical applications due to their antibacterial, antifungal, antiviral, anti-inflammatory, and antiangiogenic effects. The present study aimed to establish a simple, reliable, cost-effective, and environmentally friendly approach for the synthesis of Ag NPs in different sizes using extracts from Syzygium aromaticum and Laurus nobilis and study the relationship between the size of Ag NPs and their antibacterial and anti-biofilm effectiveness. The synthesized Ag NPs were extensively characterized using various techniques, such as XRD, SEM, UV–vis and FTIR. Importantly, the study evaluated the antibacterial and anti-biofilm activities of Ag NPs in two different size (12 nm and 45 nm) against MDR and biofilm-producing pathogenic bacteria, including Kocuria rosea, Staphylococcus sciuri, and Staphylococcus lentus. The antibacterial activity of the larger Ag NPs-SA (45 nm) ranging between 14–25 mm while for the smaller Ag NPs-LN (12 nm) ranging between 26–48 mm against pathogenic bacteria. The MIC values for Ag NPs-LN were between 16 - 32 µg/ml while for Ag NPs-SA were 64 µg/ml. The MIC value of the Ag NPs decreased as their size decreased, indicating higher potency against the tested bacterial strains. Furthermore, the smaller Ag NPs-LN exhibited a higher rate of biofilm inhibition that reach 88% compared to the larger Ag NPs that reach 70%. This study provides novel evidence that the enhanced antibacterial and anti-biofilm activities of Ag NPs are directly correlated with their decreased nanoscale size. These findings highlight the potential of Ag NPs as a promising adjuvant in the management of bacterial infections, particularly those involving MDR and biofilm-producing pathogens, which pose a significant challenge in clinical settings.

Protective role of biosynthesized silver nanoparticles synthesized using sesame oil as biocontrol approach against Erwinia amylovora causing fire blight in pears (Pyrus communis L.)

Erwinia amylovora, the primary cause of fire blight, is thought to be one of the most difficult crop diseases to eradicate. The study aimed to evaluate the performance of essential sesame oil (SO) and silver nanoparticle synthesized by sesame oil SO-AgNPs against E. amylovora. Using GC-MS, it was found that essential sesame oil contains the main component of the oil was sesamin, asarninin, heptane, c-Sitosterol, anethol, and trimethyl -6- ((s) - 4-methylcyclohexan – 3 – en-1-yl)) tetrahydro -2H-pyran. The diluted sesame oil (SO) was used as a reducing agent in synthesis of AgNPs in aqueous solution. By using UV-Visible spectrophotometry (UV–Vis), Dynamic Light Scattering (DLS), High Resolution Transmission Electron Microscopy (HRTEM), and Fourier Transformer InfraRed (FTIR) analysis, the produced Ag NPs were studied. The average particle size of the spherical Ag NPs was determined to be 54.98 nm using data from HRTEM and DLS. SO-Ag NPs (20 µg/ml) showed a promising antibacterial against E. amylovora, producing a 22.9 mm Zone of Inhibition (ZOI) against E. amylovora, followed by SO-Ag NPs (10 ug/ml) that gave 18.2 mm ZOI., compared to gentamicin that produced 13.2 mm ZOI. The most effective inducers were SO-Ag NPs at 10 ug/ml, which decreased the percentage of disease severity by 27.5 and increased the percentage of protection against disease infection by 68.39%. SO-Ag NPs was the most effective inducers which decreased the contents of Malonaldehyde (MDA) and H2O2 by 41.3% and 77.1%. Applying SO-Ag NPs or SO lowered the level of malondialdehyde (MDA) and hydrogen peroxide (H2O2) and improved the fruit set and yield in infected trees. We could assume that, to prevent E. amylovora fire blight disease in pears, SO-Ag NPs, SO are safe, effective, and environmentally friendly alternatives to conventional antibiotics.

Characterization and Biological Activity of Silver Nanoparticles from (Rhizophora Mucronata) Mangrove Extract

In this study, silver nanoparticles (AgNPs) were biosynthesized from a crude leaf extract of Rhizophora mucronata. The initial phytochemical analysis of the sample revealed the presence of tannins, steroids, terpenoids, saponins and flavonoids which contribute to the reduction and stabilization of silver ions during the synthesis process. Characterization techniques, including FTIR, UV–Vis spectroscopy, SEM and EDS, confirmed the successful synthesis of AgNPs with distinctive properties. The UV–Vis spectra exhibited an absorption peak around 420 nm, characteristic of AgNPs. SEM images revealed the crystal nature of the nanoparticles, indicating structural stability. The agar well-diffusion method was employed to determine the zone of inhibition against different pathogens. The leaf extract demonstrated the highest antibacterial potential, with substantial zones of inhibition observed against all tested pathogens. The potent anti-inflammatory activity showed the minimum and maximum inhibition of protein denaturation at concentration of 25 [Formula: see text]g/mL and 100 [Formula: see text]g/mL are 28% and 69%, respectively. The silver nanoparticles demonstrated anti-inflammatory properties by inhibiting protein denaturation, suggesting their potential therapeutic applications. The mangrove R. mucronata leaf extract decided to be a favorable reducing agent for the biological synthesis of silver nanoparticles with potent antimicrobial activity.

A time and temperature dependent biosynthesis of silver nanoparticles using the extract of Platycladus orientalis’ fruit

Silver nanoparticles (AgNPs) have gained notable/ huge attention, particularly in the biomedical and antibacterial fields, owing to their distinctive characteristics. Biological synthesis of AgNPs is a prominent method due to its ease of preparation, eco-friendliness, non-toxicity and time efficiency. Herein, AgNPs were synthesized using an extract from "Platycladus orientalis" and their antimicrobial and biological properties were thoroughly investigated. The scaling down of Ag⁺ to Ag⁰ was evident through the appearance of a yellow brownish colour. AgNPs were characterized by UV–Visible spectrum, X-ray diffraction (XRD), and scanning electron microscopy (SEM). UV–Visible spectroscopy revealed absorption peaks at around 440 nm for AgNPs synthesized from fruits’ seat coat of Platycladus orientalis. TEM analysis indicates the average size of AgNPs is approximately 50 nm. Powder XRD confirmed the crystalline nature of the AgNPs, with prominent peaks corresponding to face-centred cubic structures. FTIR analysis identified key functional groups involved in the synthesis process. SEM images displayed agglomerated AgNPs with varying diameters and particle dispersion. Molecular docking results showed favourable binding interactions of AgNPs with the protein 2BTD, with a docking score of -3342 kcal/mol, indicating potential biological activity. These findings highlight the effective synthesis of AgNPs using Platycladus orientalis and their significant potential for biomedical applications.

Green Synthesis of Silver Nanoparticle from Anadenanthera colubrina Extract and Its Antimicrobial Action against ESKAPEE Group Bacteria.

Given the urgent need for novel methods to control the spread of multidrug-resistant microorganisms, this study presents a green synthesis approach to produce silver nanoparticles (AgNPs) using the bark extract from Anadenanthera colubrina (Vell.) Brenan var. colubrina. The methodology included obtaining the extract and characterizing the AgNPs, which revealed antimicrobial activity against MDR bacteria. A. colubrina species is valued in indigenous and traditional medicine for its medicinal properties. Herein, it was employed to synthesize AgNPs with effective antibacterial activity (MIC = 19.53-78.12 μM) against clinical isolates from the ESKAPEE group, known for causing high hospitalization costs and mortality rates. Despite its complexity, AgNP synthesis is an affordable method with minimal environmental impacts and risks. Plant-synthesized AgNPs possess unique characteristics that affect their biological activity and cytotoxicity. In this work, A. colubrina bark extract resulted in the synthesis of nanoparticles measuring 75.62 nm in diameter, with a polydispersity index of 0.17 and an average zeta potential of -29 mV, as well as low toxicity for human erythrocytes, with a CC50 value in the range of 961 μM. This synthesis underscores its innovative potential owing to its low toxicity, suggesting applicability across several areas and paving the way for future research.

Stimuli-responsive synthesis of silver nanoparticles applying green and chemical reduction approaches

Introduction: The current study reports the comparative stimuli-responsive synthesis of silver nanoparticles (AgNPs) with various sizes and morphologies employing Lycium ruthenicum extract and sodium citrate solutions. Methods: The morphology and size of AgNPs were regulated by varying the pH values, concentrations of the extract solution, and temperatures in the reaction medium. The prepared AgNPs were assessed via various instrumental analyses, including UV-Vis, FTIR, XRD, TEM, and DLS. Results: The L. ruthenicum extract displayed several functional groups that reduced the Ag ions to the AgNPs at different values of pH. However, the primary chemical structure of L. ruthenicum was virtually unaltered at these conditions. Variations in the pH and extract concentration of the reaction medium yielded AgNPs of different sizes and morphologies. Both bio- and chemo-synthesized AgNPs revealed a relatively dispersed sphere-shaped morphology under alkaline conditions (≈ 36 nm). Conclusion: This study introduced a simple, valuable, and green technique for stimuli-sensitive AgNPs synthesis employing the L. ruthenicum extract.

Antibiofilm Activity of Silver Nanoparticles Synthesized from Seed Extract of Garcinia Kola

Silver nanoparticles from plant extracts are novel compounds with potential antimicrobial properties. Studies on antibiofilm activity of Ag-NPs synthesized from seed extracts of Garcinnia kola (G. kola) were carried out. Garcinnia kola seed were obtained from Keffi market, Nigeria. Green synthesis of Ag-NPs from the seed was carried using 2.0mm silver-nitrate by use of standard method. The Ag-NPs synthesized from the seed were characterized using former transmission infrared (FITR) spectroscopy and scanning election microscope. The antimicrobial activity of the Ag-NPs against Klebsiella pneumonia (Kp) isolates were carried out using agar dilution method. The biofilm formation by the isolates as well as the inhibition and dissolution by Ag-NPs were eval__uated using microplate method. The functional groups detected in the Ag-NPs were N-H, C-O, N-O, and CΞC with peaks 906.5cm-1,1282.2cm-2, 13344cm-1, 1550.6cm-1 and 217.1cm-1 respectively. The size of the particles ranges from 179-296nm. The minimum inhibiting concentration (MICs) of the particles and meropenem against the isolates were 250µg/l and 4.0µg/l. The functional inhibiting concentrates of the particles were 1.0. The optical clarity of biofilm formed by the isolates was 2.073 and 2.049. the percentage biofilm inhibiting effects of the particles was highest apart. KpC (K. Pneumoniae ATCC BAA 1075) with percentage inhibit ranges from 27.28-21.67% at 80-12.5% of the MICs. The percentage inhibiting effect of Ag-NPs in with meropenem was highest at MICs but low in MIC 12.5 with percentage inhibition 28.26% and 27.18%. The Ag-NPs alone and antibacterial activity and biofilm inhibiting effect while Ag-NPs in with meropenem had effect but against isolate but with potential antibiofilm activity.

Implications of White Light-Emitting Diode-Based Photoirradiation on Green Synthesis of Silver Nanoparticles by Methanol- and Aqueous-Based Extracts of Bergenia ciliata Leaves.

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.

Harnessing Desmochloris edaphica Strain CCAP 6006/5 for the Eco-Friendly Synthesis of Silver Nanoparticles: Insights into the Anticancer and Antibacterial Efficacy.

Microalgae-mediated nanoparticle (NP) biosynthesis is a promising green synthesis method that overcomes the challenges of conventional synthesis methods. The novel Desmochloris edaphica strain CCAP 6006/5 was isolated, purified, and characterized morphologically and genetically. GC-MS analysis of the algal biomass (DBio) phytochemicals showed the abundance for elaidic acid (18.36%) and monoolein (17.37%). UV-VIS spectroscopy helped analyze the effects of the AgNO3 concentration, algal/silver nitrate ratio, temperature, reaction time, illumination, and pH on AgNP synthesis. DBio extract or cell-free medium (DSup) of D. edaphica successfully biosynthesized small silver NPs (AgNPs), namely, DBio@AgNPs and DSup@AgNPs, under optimum reaction conditions. TEM and SEM showed a quasi-spherical shape, with average diameters of 15.0 ± 1.0 nm and 12.0 ± 0.8 nm, respectively. EDx and mapping analyses revealed that silver was the main element, the NP hydrodynamic diameters were 77.9 and 62.7 nm, and the potential charges were -24.4 and -25.8 mV, respectively. FTIR spectroscopy revealed that the DBio@AgNPs, and DSup@AgNPs were coated with algal functional groups, probably derived from algal proteins, fatty acids, or polysaccharides, representing reductant and stabilizer molecules from the synthesis process. They showed significant anticancer activity against breast cancer cells (MCF-7), low toxicity against normal kidney cells (Vero), and potent inhibitory activity against Staphylococcus aureus, Bacillus subtilis, and Shigella flexneri. D. edaphica is a novel biomachine for synthesizing small, stable and potent therapeutic AgNPs.

Green synthesis and antibacterial-antibiofilm properties of biogenic silver nanoparticles

The biosynthesis of metallic nanoparticles is gaining prominence as an alternative to traditional physicochemical methods, offering several advantages such as simplicity, non-toxicity, lower energy requirements and short reaction times leading to environmentally sustainable processes. The aims of this work were: to study the extracellular biosynthesis of silver nanoparticles (AgNPs) by Pseudomonas extremaustralis 2E-UNGS, to characterise the shape, monodispersity and size of AgNPs, to explore their antimicrobial and antibiofilm activities, and to evaluate the role of nitrate reductase activity in the biosynthesis process. The novelty of this work relies on the development of a green and sustainable method for the synthesis of stable AgNPs with optimal properties for potential applications in antimicrobial materials, especially when incorporated into polymeric matrices or used as agrochemical substitutes. Optimal conditions for the biosynthesis of spherical AgNPs were determined to be pH 7, 38 °C, 4 h of darkness and 120 rpm using stationary phase culture supernatants of P. extremaustralis 2E-UNGS. The involvement of extracellular nitrate reductase in AgNP biosynthesis was confirmed by enzymatic assays and supported by bioinformatics analysis, which identified the presence of the napA2 gene linked to the nirBD cluster. Antimicrobial assays demonstrated the inhibitory effect of AgNPs against both Gram-positive and Gram-negative bacteria, including Pseudomonas aeruginosa PA01 in both planktonic and biofilm states. In addition, the potential application of AgNPs in innovative antibacterial polymers was explored by incorporating them into polyurethane matrices either alone (PU-AgNP) or in combination with crystal violet as a photosensitizer (PU-AgNP-CV). Subsequent inoculation with a clinical isolate of Pseudomonas aeruginosa resulted in significant reductions in viable bacterial counts on both PU-AgNP-CV and PU-AgNP. Biogenic AgNPs showed antibacterial and antibiofilm properties for new antimicrobial material development.

Development of a colorimetric sensor for selective manganese detection using green-synthesized silver nanoparticles from Withania somnifera

This study reports the green synthesis of silver nanoparticles (AgNPs) using the fruit extract of Withania somnifera and their application as a colorimetric sensor for selective manganese (Mn2+) ion detection. The synthesis of AgNPs was optimized by varying pH, reaction time, and concentrations of fruit extract and AgNO3. UV–visible spectroscopy revealed that the highest absorbance of AgNPs occurred at pH 11, indicating optimal conditions for NPs formation. The absorbance behavior over time demonstrated the nucleation and stabilization processes, with optimal stability achieved after 1800 min. Increasing concentrations of fruit extract and AgNO3 enhanced NPs synthesis, reaching a plateau at 1.0 mL of extract and 1.0 mM AgNO3, respectively. Transmission electron microscopy (TEM) confirmed the formation of spherical AgNPs of 43–85 nm. Fourier-transform infrared spectroscopy (FTIR) indicated the involvement of functional groups such as O-H and C=O in the reduction and stabilization of AgNPs. The green-synthesized AgNPs exhibited notable antioxidant activity, with moderate free radical scavenging abilities compared to ascorbic acid. The colorimetric detection of Mn2+ was achieved through the aggregation of AgNPs, leading to a visible color change. UV–vis absorption spectra showed a prominent peak at 412 nm, with a linear relationship between absorbance change and Mn2+ concentration, demonstrating high sensitivity and selectivity. Comparative studies with other metal ions (Co2+, Cr3+, Ni2+) confirmed the specificity of AgNPs towards Mn2+. In conclusion, the green-synthesized AgNPs from W. somnifera offer a cost-effective and environmentally friendly approach for Mn2+ detection, with significant potential for environmental monitoring and biomedical applications.

Biosynthesized Silver Nanoparticles from Cyperus conglomeratus Root Extract Inhibit Osteogenic Differentiation of Immortalized Mesenchymal Stromal Cells.

Silver nanoparticles (AgNPs) are a focus of huge interest in biological research, including stem cell research. AgNPs synthesized using Cyperus conglomeratus root extract have been previously reported but their effects on mesenchymal stromal cells have yet to be investigated. The aim of this study is to investigate the effects of C. conglomeratus-derived AgNPs on adipogenesis and osteogenesis of mesenchymal stromal cells. AgNPs were synthesized using C. conglomeratus root extract, and the phytochemicals involved in AgNPs synthesis were analyzed using gas chromatography-mass spectrometry (GCMS). The cytotoxicity of the AgNPs was tested on telomerase-transformed immortalized human bone marrow-derived MSCs-hTERT (iMSC3) and human osteosarcoma cell line (MG-63) using MTT and apoptosis assays. The uptake of AgNPs by both cells was confirmed using inductively coupled plasma-optical emission spectrometry (ICP-OES). Furthermore, the effect of AgNPs on iMSC3 adipogenesis and osteogenesis was analyzed using stain quantification and reverse transcription- quantitative polymerase chain reaction (RT-qPCR). The phytochemicals predominately identified in both the AgNPs and C. conglomeratus root extract were carbohydrates. The AgNP concentrations tested using MTT and apoptosis assays (0.5-64 µg/ml and 1,4 and 32 µg/ml, respectively) showed no significant cytotoxicity on iMSC3 and MG-63. The AgNPs were internalized in a concentration-dependent manner in both cell types. Additionally, the AgNPs exhibited a significant negative effect on osteogenesis but not on adipogenesis. C. conglomeratus-derived AgNPs had an impact on the differentiation capacity of iMSC3. Our results indicated that C. conglomeratus AgNPs and the associated phytochemicals could exhibit potential medical applications.

Fabrication of electrospun PA66 nanofibers loaded with biosynthesized silver nanoparticles: investigation of dye degradation and antibacterial activity.

In the current study, silver nanoparticles (AgNPs) incorporated Polyamide 66 (PA66) nanofiber mat as a photocatalyst which was prepared using electrospinning technique for degradation of methyl orange (MO). Considering the lack of reported studies on the influence of the ultrasonication on the size and stability of AgNPs, the purpose of the study was to produce a small size of AgNPs and compare it with the continuous stirring method. It is reasonable to report that the advantage of ultrasonication is to generate relatively smaller AgNPs (u-AgNPs) compared to fabrication by continuous stirring method (s-AgNPs). Helichrysum arenarium (HA) extract was used as a reducing agent as well as a capping agent in green synthesis of AgNPs. AgNPs were characterized by UV-visible spectrophotometry, Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and transmission electron microscope (TEM). PA66/u-AgNs nanofibers were then successfully electrospun and characterized by using scanning electron microscope (SEM), FT-IR, thermal gravimetric analysis (TGA), and water contact angle measurement (WCA). Fabricated PA66-based nanofiber mat with smooth surface and uniform diameters (330-340nm) was used as a catalyst in MO degradation. PA66/u-AgNP nanofibers were also evaluated for antibacterial performance and showed significant inhibition against Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa bacteria. According to these findings, it is expected that the fabricated novel PA66/u-AgNP nanofibers can be announced as a promising potent and applied to the wastewater applications.

From Ficus recemosa Leaf Galls to Therapeutic Silver Nanoparticles: Antibacterial and Anticancer Applications.

The synthesis of silver nanoparticles (AgNPs) using environmentally friendly methods has become increasingly important due to its sustainability and cost-effectiveness. This study investigates the green synthesis of AgNPs using gall extracts from the plant Ficus recemosa, known for its high phytochemical content. The formation of AgNPs was verified through multiple analytical techniques, including UV-Vis spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), zeta potential analysis, and dynamic light scattering (DLS). The UV-Vis spectroscopy results displayed a distinct surface plasmon resonance peak indicative of AgNP formation. FTIR analysis revealed specific interactions between silver ions and phytochemicals in the gall extract, while TEM images confirmed the nanoscale morphology and size of the synthesized particles. Zeta potential and DLS analyses provided insights into the stability and size distribution of the AgNPs, demonstrating good colloidal stability. Biological properties of the AgNPs were assessed through various assays. Antimicrobial activity was tested using the disc diffusion method against Escherichia coli and Staphylococcus aureus, showing significant inhibitory effects. The anticancer potential was evaluated using the trypan blue exclusion assay on Dalton's Lymphoma Ascites (DLA) cells, revealing considerable cytotoxicity. Additionally, antimitotic activity was studied in the dividing root cells of Allium cepa, where the AgNPs significantly inhibited cell division. This research highlights the effective use of F. recemosa gall extracts for the green synthesis of AgNPs, presenting an eco-friendly approach to producing nanoparticles with strong antimicrobial, anticancer, and antimitotic properties. The promising results suggest potential applications of these biogenic AgNPs in medical and agricultural sectors, paving the way for further exploration and utilization.

Biofouling control of thermophilic bacteria in membrane distillation

Previously, fouling of MD membranes was perceived to be minimal due to the operational conditions preventing bacterial growth. However, recent studies presented fouling of MD membranes, largely due to various halophilic and thermophilic bacterial. The current study presented potential of antibacterial cellulose nanocrystals (CNCs) capped silver nanoparticles (AgNPs) towards biofouling control in MD water desalination processes. Interestingly, the CNCs were used as capping and reducing agent in a microwave mediated synthesis of AgNPs. The green synthesis approach of AgNPs and its successful use in MD processes was reported for the first. The MD experiments were carried out using a series of modified PVDF membranes and feed solution spiked with a thermophilic G. stearothermophilus. Upon evaluation of fouled membranes, particularly PVDF, PVP-equipped PVDF, and f-CNTs-modified PVDF, the surface energy of interactions were −131 mJ/m2, −31.5 mJ/m2, −28.6 mJ/m2, suggesting favorable interaction between the membranes and bacterial foulant. The findings of this study were supported by fouling layer and bacterial growth as seen from scanning electron microscopy, atomic force microscopy and Fourier transform infrared results. Upon membrane surface modification using CNCs-capped AgNPs, bacterial growth on membrane surface was reduced. Specifically, the positive cohesion energy between the CNCs-capped AgNPs-modified PVDF membrane and thermophilic bacterial foulant was + 63.2 mJ/m2, distinctly proving reduced fouling. The findings were supported by 5.5 % flux decay of the modified membrane compared to 79.3 % flux decay of virgin PVDF membrane. This suggested a long-term membrane integrity in thermophilic bacterial contaminated feed solutions during the MD water desalination.

Development of AgNPs-PVP/TPU based flexible strain sensors for structural health monitoring of composite structures

Real-time in-stu structural health monitoring (SHM) of composite structure developed through highly sensitive and flexible smart sensors based on colloidal solution of Silver Nano Particles (AgNPs). Synthesis of AgNPs through chemical reduction method by citrate and then in Haxen phase transferred by using surfactant Cetyltrimethylammonium bromide (CTAB). Colloidal solution of AgNPs-Haxen and Polyvinylpyrrolidone (PVP) - Haxen has been followed by mixed, calcined and deposited that thick paste on flexible Thermoplastic Polyurethane (TPU) film. These sensors become more sensitive than metallic foil made sensors and farther this sensor pasted on polymer composite for monotonic loading like tensile loading. The data extracted from sensors was monitored effectively by data acquisitioning technique using Keithley KUSB-3100. This research based on chemical synthesis of metallic nanoparticles like silver, its functionalization, protection of these nanoparticles from environment by capping agents and by creating inert atmosphere respectively. Then these functionalized capped nanoparticles are embedded on the surface of thermoplastic Urethane (TPU) film to make piezo resistive semi conductive strips which serve as flexible strain gauge/smart sensor. One other technique is also being used to make sensor is that colloidal solution of metallic Nanoparticles sprays over TPU substrate using Connective Self Assembly (CSA) method. The sensor then properly attached to Glass fabric reinforced polymer (GFRP) composite and calibrated using data acquisitioning (DAQ) under different mode of testing.

Biosynthesis of Silver and Gold Nanoparticles Using Geum urbanum L. Rhizome Extracts and Their Biological Efficiency

AbstractThe present study evaluates the biosynthesis of AgNPs and AuNPs using aqueous and ethanolic Geum urbanum L. rhizome extracts. The biosynthesized metal nanoparticles (MNPs) were characterized using UV-Vis spectroscopy, FTIR, DLS, SEM, EDX, and TEM. The UV-Vis spectra confirmed the synthesis of AgNPs and AuNPs through peaks corresponding to the surface plasmon effect of metallic Ag (400–430 nm) and Au (530–570 nm). FTIR analysis indicated that alcohols, phenols, proteins, and carbohydrates from G. urbanum rhizome extracts composition are involved in MNPs synthesis. In DLS analysis, AgNPs (34.26–41.14 nm) showed smaller hydrodynamic diameters than AuNPs (46.26–70.29 nm). At the same time, all values for zeta potential were negative, between − 21 and − 13 mV, suggesting good stabilities for all the colloidal MNPs systems in dispersion. TEM analysis showed that the biosynthesized AgNPs had a spherical morphology, while AuNPs were quasi-spherical, polygonal, and triangular. According to TEM data, AgNPs synthesized using aqueous and ethanolic G. urbanum rhizome extracts were characterized by mean diameters of 9.82 ± 3.68 and 14.29 ± 3.46 nm, while AuNPs by 15.88 ± 6.28 and 24.89 ± 10.75 nm, respectively. EDX analysis confirmed the presence of metallic Ag and Au in the MNPs composition by detecting strong signals at 3 (AgNPs) and 2.2 keW (AuNPs). In disc diffusion assay, MNPs showed good antimicrobial activity against Gram-positive (S. aureus MSSA, S. aureus MRSA, S. epidermidis) and Gram-negative (E. coli, P. aeruginosa, K. pneumoniae) bacteria and yeasts (C. albicans). AgNPs and AuNPs were also characterized by a significant antioxidant potential, evaluated through in vitro assays (lipoxygenase inhibition, DPPH radical scavenging activity, metal ion chelating activity, and hydroxyl radical scavenging assays). An overall better activity was obtained for the ethanolic G. urbanum rhizome extract and its derived AgNPs (EC50 = 34.2 ± 1.86 mg/mL in lipoxygenase inhibition assay). Therefore, the G. urbanum rhizome extracts proved to be excellent sources for biologically active AgNPs and AuNPs.

Pomegranate’s silver bullet: Nature-powered nanoparticles deliver a one-two punch against cancer and antimicrobial resistance

Biogenic synthesis for producing silver nanoparticles (AgNPs) leverages natural extracts, offering an eco-friendly and biocompatible alternative to traditional chemical methods. Pomegranate (Punica granatum L. (PG)) extract, rich in phytochemicals, presents a valuable resource for this green synthesis approach. The primary objective is to harness the natural phytochemicals in PG extract to create stable, biocompatible AgNPs through a green synthesis method. Our study aims to explore the synthesis and characterization of AgNPs derived from PG using eco-friendly methods. In addition, this study investigates the antioxidant, antimicrobial, and anticancer properties of PG-AgNPs. The preparation of PG followed by the reduction of AgNO3 to PG-AgNPs, with subsequent characterization using UV–Vis spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). These techniques confirmed the successful synthesis of AgNPs with desirable size, shape, and stability. Further, antimicrobial properties, antioxidants, cytotoxicity assay, and ADME prediction were also assessed. The PG-AgNPs revealed no signs of aggregates, suggesting they could maintain their original shape. In addition, XRD analysis indicates that PG-AgNPs are highly pure. The zeta potentials of the biosynthesized PG-AgNPs were −17.8 ± 6.57 mV. AgNPs exhibited FTIR peaks associated with silanols, carboxylates, phosphonates, and siloxanes. The PG-AgNPs exhibited potent antibacterial activity against E. coli and Klebsiella pneumoniae, with higher efficacy than PG extract alone. Additionally, PG-AgNPs demonstrated significant antioxidant activity comparable to or exceeding that of ascorbic acid. The AgNPs effectively inhibited the growth of liver (HepG2), breast (MDA-MB-231), and cervical (HeLa) cancer cells in a dose-dependent manner while showing no toxicity to normal human cells (WI-38). The study concludes that biogenically synthesized PG-AgNPs possess potent anticancer and antimicrobial properties, highlighting their potential as therapeutic agents. The green synthesis method underscores the advantages of eco-friendly approaches in developing effective nanomaterials, paving the way for novel treatments in cancer therapy and combating antibiotic-resistant infections.

Biosynthesis of silver nanoparticle from flower extract of Dillenia indica and its efficacy as antibacterial and antioxidant

Dillenia indica is a medicinal tree of the Dilleniaceae and its flower extract was used for the synthesis of silver nanoparticle (AgNPs). The optimal conditions for AgNPs synthesis were as such: 2 mM AgNO3, pH 4.5 and 48-h reaction time. The characteristic band of AgNPs was observed at the wavelength of 435 nm by UV–visible spectroscopic study. Fourier-transform infrared (FTIR) analysis depicted the involvement of several functional groups of plant extracts in the synthesis of AgNPs. Nanoparticles were mostly spherical shaped and uniformly distributed, when observation was made by Transmission electron microscopy (TEM). Energy Dispersive X-Ray (EDX) showed absorption peak approximately at 3 keV thus confirmed the presence of silver metal in AgNP. X-ray diffraction (XRD) investigation and selected area electron diffraction (SAED) patterns showed the crystalline nature of the AgNPs. Dynamic light scattering (DLS) analysis exhibited average size of the nanoparticles as 50.17 nm with a polydispersity index (PDI) value of 0.298. The zeta potential of nanoparticles was observed as −24.9 mV. To assess antibacterial activity, both AgNPs alone or its combination with the antibiotic were tried against six pathogenic bacteria. The combination of AgNPs with antibiotic was maximum effective against Shigella boydii (16.07 ± 0.35) and Klebsiella pneumoniae (15.03 ± 0.20). AgNPs alone showed maximum inhibition for both Gram-positive bacteria: methicillin-resistant Staphylococcus aureus (19.97 ± 0.20 mm) and Enterococcus faecium (19.80 ± 0.15 mm). Maximum inhibition of Enterobactor cloacae and Pseudomonas aeruginosa was observed by antibiotic taken alone. Evaluation through 2,2-diphenyl-1-picrylhydrazyl (DPPH) and DNA nicking assays demonstrated the antioxidant capabilities of the nanoparticles.