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A rapid, eco-friendly, and simple method for the synthesis of long-lasting (2 years) silver nanoparticles (AgNPs) is reported using aqueous leaf and petal extracts of Tagetes erecta L. The particles were characterized using UV-Visible spectrophotometry and the analytical and crystallographic techniques of transmission electron microscopy (TEM). The longevity of the AgNPs was studied using UV-Vis and high-resolution TEM. The antibacterial activity of the particles against Erwinia amylovora was evaluated using the Kirby–Bauer disk diffusion method. The results were analyzed using ANOVA and Tukey's test (p ≤ 0.05). Both the leaf and petal extracts produced AgNPs, but the leaf extract (1 mL) was long-lasting and quasi-spherical (17.64 ± 8.87 nm), with an absorbance of UV-Vis λmax 433 and a crystalline structure (fcc, 111). Phenols, flavonoids, tannins, and terpenoids which are associated with -OH, C=O, and C=C were identified in the extracts and could act as reducing and stabilizing agents. The best antibacterial activity was obtained with a nanoparticle concentration of 50 mg AgNPs L−1. The main contribution of the present research is to present a sustainable method for producing nanoparticles which are stable for 2 years and with antibacterial activity against E. amylovora, one of most threatening pathogens to pear and apple productions. [ABSTRACT FROM AUTHOR]

The synthesis of Cyanobacteria‐mediated nanoparticles has attracted great attention due to its ecofriendly, cost‐effective and biocompatible properties. Silver nanoparticles (AgNPs) are used in different areas such as medicine, household products, disinfectants or food storage. The present study aimed the biosynthesis of AgNPs from Cyanobacterial Chroococcus sp. and their antimicrobial activities on some important pathogen bacterial species. According to the obtained data, optimal conditions for synthesis of AgNPs were extract rate 3 : 1 v/v (cell extract/AgNO3), silver salt concentration 10 mM, pH 7, temperature 60 °C and time 30 minutes. The surface plasmon resonance peak of AgNPs was observed at 420–430 nm, and AgNPs were well‐dispersed spherical with an average size of 11–13 nm in diameter by TEM. SEM‐EDX analysis revealed a strong signal of silver. With FTIR analyzes, shift in the absorption bands after the AgNPs formation was confirmed. X‐ray diffraction analysis exhibited that the AgNPs were cubic crystalline shape. Zeta potential of AgNPs showed ‐ 20 mV. The AgNPs strong showed antibacterial activity on an opportunistic bacterial pathogens of Micococcus luteus, Bacillus subtilis and Pseudomonas aeroginosa. The effective and rapid synthesis of Chroococcus‐mediated AgNPs and their strong antimicrobial effects can create an important potential for their use in biomedical and environmental applications. [ABSTRACT FROM AUTHOR]

Background and Aim: The use of bioengineered nanocomposites as antimicrobials has increased in recent years, but very few investigations have been conducted to test their effectiveness against Pseudomonas aeruginosa, a pathogen presenting public health risks that can impact both humans and animals. The aim of this study was to assess the antimicrobial potential of phytofabricated silver nanoparticles synthesized using lemongrass extract against clinical isolates of P. aeruginosa. Materials and Methods: The extraction of active compounds from the leaves of Cymbopogon citratus was performed using ethanol (80%) as a solvent, high-performance liquid chromatography-mass spectrometry was used to analyze the chemical composition of the extract, the synthesis of silver nanoparticles (AgNPs) was done using silver nitrate (AgNO3) as a precursor, and the antimicrobial and antibiofilm activity of the extract and the AgNPs phytofabricated was assessed against 10 clinical strains of P. aeruginosa. Results: Lemongrass extract was found to consist of the following main compounds: Caffeic acid (445.21 ± 32.77 µg/g), p-coumaric acid (393.32 ± 39.56 µg/g), chlorogenic acid (377.65 ± 4.26 µg/g), quinic acid (161.52 ± 17.62 µg/g), and quercetin-3-glucoside (151.35 ± 11.34 µg/g). AgNPs were successfully phytofabricated using 2.5 mM AgNO3. The ultraviolet (UV)-visible absorption spectra of the AgNPs showed a localized surface plasmon resonance at 464 nm with an absorbance of 0.32 A. The 50× hydrodynamic diameter was 50.29 nm with a surface area value of 120.10 m2/cm3, and the volume mean diameter and Sauter mean diameter were 50.63 nm and 49.96 nm, respectively. Despite the compound found in lemongrass extract, no antimicrobial activity was observed with the extract, while AgNPs exhibited noteworthy dose-dependent antimicrobial activity with inhibition diameters up to 24 mm and minimum inhibitory concentration (MIC) and minimum bactericidal concentration ranging from 2 to 16 and 4-64 µg/mL, respectively. AgNPs also demonstrated significant antibiofilm activity by inhibiting biofilms up to 99% between MIC/2 and 2MIC. Conclusion: The present study suggests that lemongrass is a good candidate for the synthesis of AgNPs with good physicochemical characteristics and having a strong anti-pseudomonas activity. Further research is needed to assess the stability and safety of these AgNPs. [ABSTRACT FROM AUTHOR]

Much attention has been gained on green silver nanoparticles (green-AgNPs) in the medical field due to their remarkable effects against multi-drug resistant (MDR) microorganisms and targeted cancer treatment. In the current study, we demonstrated a simple and environment-friendly (i.e., green) AgNP synthesis utilizing Jacobaea maritima aqueous leaf extract. This leaf is well-known for its medicinal properties and acts as a reducing and stabilizing agent. Nanoparticle preparation with the desired size and shape was controlled by distinct parameters; for instance, temperature, extract concentration of salt, and pH. The characterization of biosynthesized AgNPs was performed by the UV-spectroscopy technique, dynamic light scattering, scanning electron microscopy, X-ray diffraction, and Fourier-transform infrared. The successful formation of AgNPs was confirmed by a surface plasmon resonance at 422 nm using UV-visible spectroscopy and color change observation with a particle size of 37± 10 nm and a zeta potential of −10.9 ± 2.3 mV. SEM further confirmed the spherical size and shape of AgNPs with a size varying from 28 to 52 nm. Antibacterial activity of the AgNPs was confirmed against all Gram-negative and Gram-positive bacterial reference and MDR strains that were used in different inhibitory rates, and the highest effect was on the E-coli reference strain (MIC = 25 μg/mL). The anticancer study of AgNPs exhibited an IC50 of 1.37 μg/mL and 1.98 μg/mL against MCF-7 (breast cancer cells) and A549 (lung cancer cells), respectively. Therefore, this green synthesis of AgNPs could have a potential clinical application, and further in vivo study is required to assess their safety and efficacy. [ABSTRACT FROM AUTHOR]

Nanotechnology has emerged as a promising field for the development of novel antibacterial agents with reduced environmental impact. In this study, we present a novel green synthesis approach for the production of silver nanoparticles (AgNPs) using a plant-based extract. These AgNPs were subsequently characterized using various analytical techniques, including UV-Vis spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy (FTIR). UV-Vis spectroscopy confirmed the formation of AgNPs by exhibiting a characteristic surface plasmon resonance peak at around 401 and 420 nm. XRD analysis revealed the crystalline nature of the AgNPs, with distinct diffraction peaks corresponding to the face-centered cubic structure of silver. TEM analysis demonstrated that the synthesized AgNPs were predominantly spherical in shape and exhibited an average size within the nanoscale range. FTIR analysis was employed to elucidate the potential bioactive compounds present in the plant extract responsible for the reduction and stabilization of AgNPs. Furthermore, we evaluated the antibacterial activity of these synthesized AgNPs against a panel of bacterial isolates. All the bacterial isolates were sensitive to the silver nanoparticles. Staphylococcus aureus as found to be most resistant, while E. coli as found to be the most sensitive. [ABSTRACT FROM AUTHOR]

Silver nanoparticles have special plasmonic and antibacterial characteristics that make them efficient in a variety of commercial medical applications. According to recent research, chemically synthesized silver nanoparticles are harmful even in low concentrations. It was crucial to identify appropriate synthesis methods that may have low costs and be nontoxic to the environment. Zingiber officinale (ginger) extracts used to prepare silver nanoparticles were inexpensive and environmentally friendly, and the best physicochemical characteristics were analyzed. Silver nanoparticles were characterized by using UV-visible spectroscopy, Scanning electron microscopy (SEM), and X-ray diffraction (XRD). The surface Plasmon resonance peak at 425 nm was observed using UV-Visible spectroscopy. Scanning electron microscopy observed that the nanoparticles were spherical and ranged in size from 5 to 35 nm. The XRD pattern values of 2θ: 38.2o, 46.3o, and 64.58o are used to determine the planes (111), (200), and (220). The silver nanoparticle's existence was verified by the face-centered cubic (FCC). Silver nanoparticles were found to have antibacterial efficacy against gram-positive Staphylococcus and gram-negative bacteria such as Pseudomonas aeruginosa, Klebsiella Aerogenes, Salmonella, Staphylococcus and Escherichia coli. The antibacterial activity of silver nanoparticles was observed using the agar well diffusion (AWD) method at three different concentrations (100 μg/ml, 75 μg/ml, and 50 μg/ml). The zone of inhibition measured against the bacterial strains pseudomonas Aeruginosa, Klebsiella aerogenes, Escherichia coli, Salmonella and Staphylococcus which were (18.4±1.25 mm, 16.9±0.74 mm, 14.8±1.25 mm), (16.8±0.96 mm, 14.6±0.76 mm, 14.0±1.15 mm), (19.7±0.76 mm, 18.2±0.66 mm, 15.4±1.15 mm), (16.6±0.67 mm, 14.2±0.23 mm, 12.8±0.78 mm) and (12±0.68 mm, 10±0.20 mm, 08±0.15 mm). These nanoparticles' potent antibacterial properties may enable them to be employed as nanomedicines for a variety of gram-negative bacterial illness treatments. [ABSTRACT FROM AUTHOR]

Wounds serve as an appropriate medium for the growth of pathogenic bacteria, and bacterial resistance to already available antibiotics demands new and safe approaches in the field of medicine. Silver nanoparticles (AgNPs) exhibited a wide range of applications in biomedicine and emerged as promising nano-antibiotics. The biological preparation of AgNPs by utilizing aqueous plant extract has become an encouraging alternative to traditional chemical methodologies, owing to a viable eco-friendly approach. In the present study, Lepidium didymum leaves extract was used for the biosynthesis of AgNPs-LD. The nanoparticles were characterized through UV-Vis spectroscopy, Fourier transforms infrared spectrometry (FTIR), Scanning electron microscopy (SEM), and X-ray diffraction (XRD). The antibacterial activity of AgNPs-LD was evaluated against Staphylococcus aureus, Escherichia coli, Klebsiella pneumonia, and Pseudomonas aeruginosa. Further, AgNPs-LD nanoparticles were incorporated into topical gels to evaluate their effectiveness for wound healing in the rat model. UV-visible spectra showed a surface resonance peak around 400 nm correlated with the synthesis of AgNPs; FTIR spectra verified the participation of phytochemicals present in L. didymum leaves extract in AgNPs-LD synthesis; and SEM revealed dispersed spherical nanoparticles as well as aggregated clusters. XRD analysis confirmed the crystalline nature, face-centered cubic lattice, and average crystallite size of 21.42 nm. The AgNPs-LD showed promising antibacterial activity against tested strains with a maximum zone of inhibition against P. aeruginosa and showed accelerated wound healing capacity comparable to control and standard treatments over the time course of wound healing. The current study concluded that biosynthesized AgNPs-LD nanoparticles are effective as antibacterial agents and are promising novel wound healing products for clinical applications. [ABSTRACT FROM AUTHOR]

• First ever report of Mucuna pruriens (L.) DC. callus mediated green synthesis of silver nanoparticles. • The seeds were germinated in-vitro in the modified Murashige and Skoog's medium and the in-vitro leaf was used as an explant to induce callus. • Callus was induced using various types of auxins and cytokinin's at different concentrations. The best responded callus was sub cultured and used for the study. • The antibacterial activity assay was performed against gram positive Bacilus velezensis (Accession no. MW219533) and gram-negative escherichia coli cultures. • highest antibacterial activity against E. coli (84.8%) and B. velezensis (78.1%) was shown by 0.5 mg/L pic and 2.0 mg/L BAP callus mediated AgNPs. In this paper, we describe the green synthesis of silver nanoparticles (AgNPs) using plant extracts, as well as their structural, optical, and antibacterial activities against Escherichia coli and Bacillus velezensis bacteria. For the study, several sections (root, leaves, and seed) of Mucuna pruriens , an immense medicinal herbal used to treat Parkinson's disease, were evaluated. Also, the seeds were grown in-vitro in the modified Murashige and Skoog's medium and the leaf derived callus supplemented by different phytohormones like picloram (pic), thidiazuron (TDZ), 6-benzylaminopurine (BAP) and 2-isopentenyl adenine (2-iP) were selected for this study. This is the first report of distinct callus obtained from M. pruriens and used for green nanoparticle synthesis. The prepared materials were thoroughly evaluated for structural and optical properties using XRD, FTIR, and UV-Visible spectroscopy. During synthesis, the colour changes from colourless to reddish brown, and the existence of an SPR peak in the absorption spectra confirms the formation of AgNPs. The FTIR spectra reveals the presence of phenolic group and alkyl ether groups, which were responsible for the reduction of silver ions during the green synthesis. The aqueous extracts of plant parts and callus obtained from different hormones showed very poor antibacterial activity. However, the green synthesized nanoparticles fabricated by different plant extracts showed good antimicrobial activity towards E. coli and B. velezensis bacteria. amongst the investigated results, highest antimicrobial activity against E. coli (84.8%) and B. velezensis (78.1%) was shown by AgNPs mediated by leaf extracts respectively followed by 0.5 mg/L pic and 2.0 mg/L BAP callus mediated silver nanoparticle solution. According to the findings, green produced AgNPs are promising candidates for antibacterial applications against E. coli and B. velezensis. [ABSTRACT FROM AUTHOR]

In the present investigation, green synthesis of silver nanoparticles (AgNPs) was carried out using aqueous leaf extract of Argyreia nervosa. The results of the spectral characterisation have revealed that the surface Plasmon resonance band was observed at 421 nm confirms the formation of AgNPs. The Fourier Transform Infra-red Spectroscopy result shows the reduction of silver nitrate into AgNPs by the reduction of different functional groups. Transmission Electron Microscope analysis revealed that the particles are roughly spherical and poly-disperse in shape and size, the particles are within the size range of 10–55 nm. Dynamic Light Scattering revealed that the nanoparticles were also within the range of 10–50 nm, An-AgNPs have a high negative zeta potential value of −38.9 mV. An-AgNPs showed efficient free radical scavenging activity and showed excellent antimicrobial activity. Anti-proliferative and cytotoxic effect of An-AgNPs was carried out by MTT assay against KB oral cancer cells, the IC50 value of An-AgNPs is 58.64 µg/ml. The cell's growth is arrested at the G2/M phase, so the An-AgNPs activated the Caspase 3 pathway which leads to the Apoptosis of KB oral cancer cells. So it is concluded that the green synthesised An-AgNPs have manifold functions. [ABSTRACT FROM AUTHOR]

Present review emphatically introduces the synthesis, biocompatibility, and applications of silver nanoparticles (AgNPs), including their antibacterial, antimicrobial, and antifungal properties. A comprehensive discussion of various synthesis methods for AgNPs, with a particular focus on green chemistry mediated by plant extracts has been made. Recent research has revealed that the optical properties of AgNPs, including surface plasmon resonance (SPR), depend on the particle size, as well as the synthesis methods, preparation synthesis parameters, and used reducing agents. The significant emphasis on the use of synthesized AgNPs as antibacterial, antimicrobial, and antifungal agents in various applications has been reviewed. Furthermore, the application areas have been thoroughly examined, providing a detailed discussion of the underlying mechanisms, which aids in determining the optimal control parameters during the synthesis process of AgNPs. Furthermore, the challenges encountered while utilizing AgNPs and the corresponding advancements to overcome them have also been addressed. This review not only summarizes the achievements and current status of plant-mediated green synthesis of AgNPs but also explores the future prospects of these materials and technology in diverse areas, including bioactive applications. [Display omitted] • Green chemistry approaches to synthesize silver nanoparticles (AgNPs) were reviewed. • Engineering of synthesis methods is the key approach to control the dispersion, size and shape of the AgNPs. • Environmental and health applications of AgNPs were reviewed. • Antibacterial, antimicrobial, and antifungal biological applications with respect to their tunable properties were reviewed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Silver nanoparticles (Ag NPs) were obtained by plant-mediated synthesis. • Ag NPs were characterized by SEM, UV–vis, FTIR and XRD analyses. • Ag NPs have high antibacterial activity against gram-positive and gram-negative bacteria. • Ag NPs were observed to have the potential to be used as antimicrobial and antioxidant agents. Plant-mediated synthesis of silver nanoparticles (Ag NPs) has increased its use in various biomedical applications due to its cost-effectiveness, renewable and environmentally friendly properties. Therefore, the focus of the study was to synthesize Ag NPs and to evaluate their antibacterial, and antioxidant activities by using the aqueous root extract of Ferula pseudodalliacea plant as a reducing agent. In addition, the synthesis of nanoparticles was confirmed by performing Ag NPs/Fp characterization processes. According to the findings of our research, color change due to surface plasmon resonance was confirmed by UV–vis spectrometry. The crystal properties of Ag NPs/Fp were determined according to the XRD model. Phytochemicals responsible for coating and reduction of Ag NPs/Fp were observed by FT-IR analysis. It has been shown that the therapeutic effect of Ag NPs/Fp exhibits better antimicrobial and antioxidant activity than aqueous extract. In addition, it was determined that Ag NPs/Fp structures showed the best antifungal effect against Candida albicans ATTC 90028 pathogen and gave a better zone than Rifampicin antibiotic. Therefore, studies at the molecular level and more comprehensively are required to determine the bioactive components and pharmacological effects of Ferula pseudodalliacea plant to confirm our antibacterial, antioxidant, and antifungal activity results. [ABSTRACT FROM AUTHOR]

The production of pure silver nanoparticles (Ag-NPs) with unique properties remains a challenge even today. In the present study, the synthesis of silver nanoparticles (Ag-NPs) from natural pullulan (PL) was carried out using a radiation-induced method. It is known that pullulan is regarded as a microbial polysaccharide, which renders it suitable to act as a reducing and stabilizing agent during the production of Ag-NPs. Pullulan-assisted synthesis under gamma irradiation was successfully developed to obtain Ag-NPs, which was characterized by UV-Vis, XRD, TEM, and Zeta potential analysis. Pullulan was used as a stabilizer and template for the growth of silver nanoparticles, while gamma radiation was modified to be selective to reduce silver ions. The formation of Ag-NPs was confirmed using UV–Vis spectra by showing a surface plasmon resonance (SPR) band in the region of 410–420 nm. As observed by TEM images, it can be said that by increasing the radiation dose, the particle size decreases, resulting in a mean diameter of Ag-NPs ranging from 40.97 to 3.98 nm. The XRD analysis confirmed that silver metal structures with a face-centered cubic (FCC) crystal were present, while TEM images showed a spherical shape with smooth edges. XRD also demonstrated that increasing the dose of gamma radiation increases the crystallinity at a high purity of Ag-NPs. As examined by zeta potential, the synthesized Ag-NP/PL was negatively charged with high stability. Ag-NP/PL was then analysed for antimicrobial activity against Staphylococcus aureus, and it was found that it had high antibacterial activity. It is found that the adoption of radiation doses results in a stable and green reduction process for silver nanoparticles. [ABSTRACT FROM AUTHOR]