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In this work, silver nanoparticles (AgNPs) were synthesized from cashew nutshell liquid (CNSL) by varying the concentration of silver ions and the pH of the CNSL extract. The synthesized AgNPs were further characterized to study their surface, structural, and morphological properties and tested for the removal of methylene blue (MB) dye. The results of this study showed that depending on the conditions, particles of various sizes, ranging from 1 to 60 nm, and different degrees of stabilization and agglomeration were produced. The concentration of silver ions equal to 3 mM and the pH of the extract of ~4.5 (AgNP3) resulted in the most efficient synthesis, where particles appeared to be highly stabilized and homogeneously distributed on the surface, exhibiting a small average particle size and a narrow particle size distribution (6.7 ± 6.5 nm). Such particles further showed the highest percent removal of MB, where up to 80% removal was recorded within the first 20 min. Higher concentrations of silver ions and higher pH of the extract resulted in substantial particle agglomeration and particles being over-capped by the CNSL biomolecules, respectively, which further negatively affected the ability of particles to remove MB. Finally, the fact that visible light showed no significant effect on the removal of MB, with the average removal rates found to be about the same as in the dark, suggests the strong catalytic nature of AgNPs, which facilitates the electron transfer reactions leading to MB reduction.

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.

The present study investigated the synthesis and biological applications of green, economical, and multifunctional silver and gold nanoparticles (TSAgNPs and TSAuNPs) using the ethnomedical important medicinal plant Thespesia lampas for biological activities. Relatively higher levels of antioxidant components were measured in T. lampas compared to the wellknown Adhatoda vasica, and Diplocyclos palmatus suggested the potential of T. lampas for the study. Synthesized TSAgNPs and TSAuNPs were characterized through UV–Vis, XRD, SEM-EDS, HR-TEM, SAED, and FTIR techniques. SEM revealed that TSAgNPs and TSAuNPs were predominantly spherical in shape with 19  ±  7.3 and 43  ±  6.3  nm crystal sizes. The sizes of TSAgNPs and TSAuNPs were found to be12  ±  4.8 and 45  ±  2.9  nm, respectively, according to TEM measurements. The FTIR and phytochemical analyses revealed that the polyphenols and proteins present in T. lampas may act as bio-reducing and stabilizing agents for the synthesis. Synthesized NPs exhibited enhanced scavenging properties for ABTS and DPPH radicals. TSAgNPs and TSAuNPs were able to protect DNA nicking up to 13.48% and 15.38%, respectively, from oxidative stress. TSAgNPs possessed efficient antibacterial activities in a concentration-dependent manner against human pathogenic bacteria, such as E. coli, B. subtilis, P. vulgaris, and S. typhi. Furthermore, TSAgNPs and TSAuNPs showed significant cytotoxicity against FaDu HNSCC grown in 2D at 50 and 100  μg  mL−1 . Tumor inhibitory effects on FaDu-derived spheroid were significant for TSAgNPs > TSAuNPs at 100  μg  mL−1 in 3D conditions. Dead cells were highest largely for TSAgNPs (76.65%  ±  1.76%), while TSAuNPs were non-significant, and Saq was ineffectively compared with the control. However, the diameter of the spheroid drastically reduced for TSAgNPs (3.94 folds) followed by TSAuNPs (2.58 folds), Saq (1.94 folds), and cisplatin (1.83 folds) at 100  μg  mL−1 . The findings of the study suggested the bio-competence of TSAgNPs and TSAuNPs as multi-responsive agents for antioxidants, DNA protection, antibacterial, and anti-tumor activities to provide a better comprehension of the role of phytogenic nanoparticles in healthcare systems. [ABSTRACT FROM AUTHOR]

Living organisms, particularly humans, frequently encounter microorganisms such as bacteria, fungi, and viruses in their surroundings. Silver nanoparticles are widely used in biomedical devices because of their antibacterial and antiviral properties. The study evaluates the efficacy of red laser and silver nanoparticles from grape seed extract (AgNPs-GSE) in reducing Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria, which cause infections. The sample comprised three groups: a control group without laser irradiation (T0), Escherichia coli samples (A1 and A2) irradiated with a 405-nm diode laser at different times and concentrations of silver nanoparticles, and Staphylococcus aureus samples (A3 and A4) illuminated with a 405-nm diode laser at different times and concentrations. Bacteria in groups A2 and A4 were treated with a photosensitizer (PS) made from grape seed extracts, incubated for 10 min, and then irradiated for 90, 120, 150, and 180 s. The samples were cultured on TSA media, set at 37 °C, counted using a Quebec colony counter, and analyzed using ANOVA and Tukey tests with a significance level of p < 0.05. The study illustrated that the combination of 10 µl of AgNPs-GSE, exposure to a red laser at 405 nm, and an energy density of 3.44 J/cm2 effectively photoinactivated both Escherichia coli and Staphylococcus aureus bacteria. For Escherichia coli bacteria irradiated for 180 s with concentrations of 1 mM, 1.5 mM, and 2 mM AgNPs-GSE, bacterial viability decreased by 64.50%, 70.74%, and 79.53%, respectively. Similarly, Staphylococcus aureus bacteria, subjected to irradiation for 180 s with concentrations of 1 mM, 1.5 mM, and 2 mM AgNPs-GSE, demonstrated reductions in bacterial viability by 70.23%, 73.47%, and 85.04%, respectively. The findings from the present study indicate that at an energy density of 3.44 J/cm2, it was possible to inactivate Escherichia coli by 79.53% and Staphylococcus aureus by 85.04%. [ABSTRACT FROM AUTHOR]

Recently there have been a variety of methods to synthesize silver nanoparticles, among which the biosynthesis method is more noticeable due to features like being eco-friendly, simple, and cost-efficient. The present study aims for the green synthesis of silver nanoparticles from the extract of the three plants A. wilhelmsi, M. chamomilla, and C. longa; moreover, it pledges to measure the antibacterial activity against some variants causing a skin rash. The morphology and size of the synthesized silver nanoparticles were evaluated by UV.vis, XRD, SEM, and FTIR analyses. Then results showed a color alteration from light yellow to dark brown and the formation of silver nanoparticles. The absorption peak with the wavelength of approximately 450 nm resulting from the Spectrophotometry analysis confirmed the synthesis of silver nanoparticles. The presence of strong and wide peaks in FTIR indicated the presence of OH groups. The SEM results showed that most synthesized nanoparticles had a spherical angular structure and their size was about 10 to 20 nm. The highest inhibition power was demonstrated by silver nanoparticles synthesized from the extract combined from all three species against Gram-positive bacteria Staphylococcus aureus and Staphylococcus epidermidis (23 mm) which had a performance far more powerful than the extract. Thus, it can be understood that the nanoparticles synthesized from these three species can act as potential environment-friendly alternatives to inhibit some variations causing skin disorders; an issue that calls for further clinical studies. [ABSTRACT FROM AUTHOR]

The rise in antibiotic resistance (AR) poses an imminent threat to human health. Nanotechnology, together with mechanisms such as quorum sensing (QS), which relies on communication between bacterial cells, may decrease the selective pressure for AR. Thus, this study aimed to investigate the effectiveness of silver nanoparticles (AgNPs) synthesized at room temperature (Rt) and 80 °C using Embelia ruminata leaf, stem-bark, and fruit extracts as antibacterial and anti-QS agents. The phytosynthesized AgNPs solutions were subjected to various characterization assays and assessed for their antibacterial activities. Quantitative QS assays were performed using Chromobacterium subtsugae CV017 and Chromobacterium violaceum ATCC 12472. Synthesized AgNPs were spherical-to-near-spherical in shape, poly-dispersed, and crystalline, with a size range of 21.06–32.15 nm. Fruit AgNPs showed stronger antibacterial activity than AgNPs from other plant organs against selected bacterial strains. In the QS assays, fruit 80 °C AgNPs demonstrated the most significant violacein inhibition in an assay performed using the short-chain acyl homoserine lactone CV017 biosensor, while the leaf and fruit Rt AgNPs demonstrated the most violacein inhibition in an assay performed using the long-chain acyl homoserine lactone ATCC 12472 biosensor. The investigations carried out in this study lay the groundwork for future innovative research into antibacterial and anti-QS strategies using E. ruminata. [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]

The green synthesis of silver nanoparticles (AgNPs) using the cell-free supernatant of a Haematococcus pluvialis culture (CFS) was implemented in the current study, under illumination conditions. The reduction of Ag+ to AgNPs by the CFS could be described by a pseudo-first-order kinetic equation at the temperature range tested. A high reaction rate during synthesis and stable AgNPs were obtained at 45 °C, while an alkaline pH (pH = 11.0) and a AgNO3 aqueous solution to CFS ratio of 90:10 (v/v) proved to be the most effective conditions in AgNPs synthesis. A metal precursor (AgNO3) at the concentration range tested (1–5 mM) was the limited reactant in the synthesis process. The synthesis of AgNPs was accomplished under static and agitated conditions. Continuous stirring enhanced the rate of reaction but induced aggregation at prolonged incubation times. Zeta potential and polydispersity index measurements indicated stable AgNPs and the majority of AgNPs formation occurred in the monodisperse phase. The X-ray diffraction (XRD) pattern revealed the face-centered cubic structure of the formed AgNPs, while TEM analysis revealed that the AgNPs were of a quasi-spherical shape with a size from 30 to 50 nm. The long-term stability of the AgNPs could be achieved in darkness and at 4 °C. In addition, the synthesized nanoparticles showed antibacterial activity against Escherichia coli. [ABSTRACT FROM AUTHOR]

This study explores an eco-friendly approach to synthesizing silver nanoparticles (AgNPs) using soybean leaf extracts, employing a reaction with silver nitrate at 65 °C for 2.5 h. Optimal results were achieved at extract concentrations of 3.12 and 6.25 mg of the leaf mL−1, termed 3.12AgNP and 6.25AgNP, respectively. UV-Vis spectrophotometric analysis between 350 and 550 nm exhibited a peak at 410–430 nm, along with a color transition in the suspensions from pale yellow to brown, indicating successful synthesis. Dynamic light scattering (DLS) further delineated the favorable properties of these AgNPs, including nanometric dimensions (73–104 nm), negative charge, and moderate polydispersity, portraying stable and reproducible synthesis reactions. The bioreduction mechanism, possibly expedited by leaf extract constituents such as amino acids, phenolic acids, and polysaccharides, remains to be fully elucidated. Notably, this study underscored the potent nematicidal effectiveness of biosynthesized AgNPs, especially 6.25AgNP, against Pratylenchus brachyurus, which is a common plant-parasitic nematode in tropical soybean cultivation regions. In vitro tests illustrated significant nematicidal activity at concentrations above 25 µmol L−1, while in vivo experiments displayed a pronounced nematode population diminishment in plant roots, particularly with a 6.25AgNP rhizosphere application at concentrations of 500 µmol L−1 or twice at 250 µmol L−1, attaining a reproduction factor below 1 without any morphological nematode alterations. This research highlights the potential of 6.25AgNPs derived from soybean leaf extracts in forging sustainable nematicidal solutions, marking a significant stride toward eco-friendly phytonematode management in soybean cultivation. This novel methodology signals a promising avenue in harnessing botanical resources for nematode control and propelling a greener agricultural horizon. [ABSTRACT FROM AUTHOR]

In this study, designed as a dye-sensitive solar cell material which, bis-(2-(4-methylthiazol-5-yl) ethoxy) phthalocyaninato silicon (IV) compound (3) was obtained from the chemical reaction of SiPcCl2 and 4-methyl-5-thiazoleethanol. Silver nanoparticles (AgNPs) were synthesized using environmentally friendly and cost-effective green methods using leaf and flower extracts of Corydalis cava(CoV) and Nonea pulla(NP) plants. For the characterization of phthalocyanine compound and silver nanoparticles, Transmission electron microscopy (TEM), ¹H NMR, 13C NMR, X-Ray Diffraction (XRD), UV-visible, FT-IR and Mass spectrum devices were used. The power conversion efficiency of without doping compound 3 is 1.20. After doping this compound with CoVAgNPs and NPAgNPs, the power conversion efficiencies increased to 1.74 and 2.10. From this it is clearly seen that silver nanoparticles are effective. It is concluded that better photovoltaic materials can be created by using phthalocyanine and silver nanoparticles together. [ABSTRACT FROM AUTHOR]

Introduction: Traditional chewing sticks from Vernonia amygdalina and Citropsis articulata have been used for oral hygiene in African rural communities. This study pioneers an eco-friendly approach to silver nanoparticle (AgNP) synthesis using stem extracts from these medicinal plants, addressing environmental concerns associated with conventional methods. The antibacterial properties of the AgNPs against oral bacterial strains are assessed, offering a sustainable solution for oral health care. Methods: AgNPs were synthesized using aqueous and ethanolic stem extracts of V. amygdalina and C. articulata. Characterization was performed using UV-visible and FTIR spectroscopy. Phytochemical analysis revealed a diverse profile of bioactive compounds, with ethanolic extracts showing greater diversity. The AgNPs were tested against 100 bacterial isolates from dental caries patients at the Federal Medical Center, Abeokuta. Results: Molecular identification revealed three prevalent bacterial isolates: Bacillus fungorum (strain CUAB-AKINTOLA01), Klebsiella pneumonia (strain CUAB-AKINTOLA02), and K. pneumonia (strain CUAB-AKINTOLA03). The extracts from V. amygdalina and C. articulata, as well as the biofabricated AgNPs, showed significant antibacterial activity against these oral pathogens. Notably, AgNPs from V. amygdalina exhibited higher zones of inhibition, with B. fungorum being the most susceptible. These findings suggest the potential of these eco-friendly AgNPs as an effective antibacterial agent against oral bacterial infections. Conclusion: This study highlights the potent antibacterial efficacy of V. amygdalina and C. articulata stem extracts, as well as the silver nanoparticles biosynthesized from these extracts, against oral bacterial pathogens. While these findings are promising, further investigations are necessary to fully elucidate the therapeutic potential of these eco-friendly agents in the prevention and treatment of dental plaque-associated diseases. [ABSTRACT FROM AUTHOR]

In this study, silver nanoparticles (AgNPs) were prepared using a green synthesis method. The optical and structural properties of these AgNPs were studied with UV-vis spectroscopy, X-ray diffraction, FE-SEM and TEM. In the UV-vis absorption spectrum, the highest peak appeared at 400 nm. The AgNPs produced had a nanocrystalline cubic structure with a crystallite size of (9.25-18.61) nm, according to the X-ray pattern. The FESEM data demonstrated that the synthesised AgNPs combine. AgNPs examined by TEM at different magnifications revealed that most particles were spherical and evenly scattered. According to the TEM histogram, the particles were highly monodispersed AgNPs with an average diameter of 45 nm. An infrared thermal imaging technique (IRT) was used to clarify the change in temperature when the AgNPs affected the skin. The material was placed on the skin in two ways and on the feet of rabbits. When the AgNPs were mixed with distilled water, a decrease in temperature was noticed, likely due to the role of water in cooling the skin. When the AgNPs were mixed with commercial Vaseline, a slight increase in the skin temperature was observed. The radiance related to the change of temperature in two bands (3-5 and 8-14 μm) was calculated. The highest value in the range 3-5 μm was 0.8730 at the maximum temperature of 32.1 °C while the highest value of the 8-14 μm band was 0.5621 at a maximum temperature of 37.1 °C. The total spectral radioactive emission is proportional to the area under the curves and shifts towards shorter wavelengths with increasing temperature. By comparing data from line profiles from different temperatures, radial heat diffusion is observed, causing energy to be transmitted to the surrounding regions from the immersed nanoparticles. [ABSTRACT FROM AUTHOR]

Nanoparticles are synthesized by using various chemical methods in higher yields but they are not very environmentally friendly and have hazardous effects on living cells. This can be attributed to the overuse of hazardous chemicals involved in the process. The green approach of nanoparticle synthesis is widely gaining attention worldwide as it is considered as nontoxic, harmless and ecofriendly. Apart from this they also have multiple applications in various fields of science and technology. Nanoparticles synthesized by using various phytochemicals are also effective against a variety of microbial populations. The objective of this study is to synthesize silver nanoparticles (AgNPs) from the fruit extracts of Wrightia tinctoria and evaluating its antimicrobial capacities against gram-positive and negative bacterial strains. Silver nanoparticles were synthesized using different solvent extracts of Wrightia tinctoria pods. The formation of silver nanoparticles was noted by detecting the change in color of the solution. The presence of nanoparticles was detected by performing UV visible spectroscopy and monitoring the spectrum from 400 nm to 800 nm. A small peak at 425 nm suggested the presence of silver nanoparticles. In a later part of the study, the inhibitory effect of green synthesized silver nanoparticles on the growth of E. coli and S. aureus was monitored. The appearance of a zone of inhibition further confirmed the antimicrobial effect of the synthesized nanoparticles. [ABSTRACT FROM AUTHOR]

Silver nanoparticles have long been known for their antibacterial properties. Recently, increasing numbers of studies confirm that they have antifungal properties as well. Due to the increasing number of these studies, this review was performed, summarizing most of the research conducted so far in this field and presenting the results of the activity of silver nanoparticles against fungal pathogens of humans and plants, green synthesis of silver nanoparticles, and the mechanism of action. The combined activity with antifungal drugs and toxicity assessment is also presented. The review describes the antifungal activity of silver nanoparticles against pathogens such as F. oxysporum, F. graminearum, T. asahii, B. cinerea, P. concavum, and Pestalotia sp. as well as many species of the genus Candida. The green synthesis of these nanoparticles has been carried out from many species of plants and microorganisms. The research cited in this review confirms the fact that silver nanoparticles obtained using green synthesis exhibit antifungal activity and can therefore be an excellent alternative to the chemical synthesis of these particles. All this proves that silver nanoparticles have a great potential to be used as a potential antifungal agent in the future. [ABSTRACT FROM AUTHOR]

Conventional remediation techniques have become outdated and insufficient to treat the influx of pollution from different fronts (air, water, and soil). Green synthesis of nanoparticles is an eco-friendly approach to remediate these contaminants and Membrane technology is increasingly becoming popular for the treatment of wastewater due to their efficiency and versatility against a wide array of contaminants. Cellulose acetate (CA) is a polymer obtained from cellulose and hence considered biodegradable, making it a more environmentally friendly option over other conventional polymers. In this present study, silver nanoparticles were synthesized using Staphylococcus aureus and characterized by UV-vis Spectrometer, Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Analysis (EDAX). The synthesized green silver nanoparticles were assimilated onto synthesized CA membrane films to fabricate nanocomposite membranes (CA-X, CA-X1 and CA-X2). EDAX results showed higher counts of silver at 3keV on the CA-X, confirming that silver nanoparticles were properly embedded on the membrane. Physio-chemical tests performed on the collected sewage, showed that the total dissolved solids (TDS) were found to decrease significantly during the first hour of treatment, CA-X1 showed 16.2% decrease and 21.95% decrease was observed by CA-X2. A decrease in total nitrogen content by 38.88% and 41.36% for CA-X1 and CA-X2 respectively was recorded after a week's treatment. Therefore, the work displayed the capability of cellulose acetate nanocomposite membrane for leachate treatment, since it displayed its potential in remediating leachate in a short span of time and scalability could be achieved for a larger volume of leachate with larger nanocomposite membranes. [ABSTRACT FROM AUTHOR]

Herein we present the results of optimization of silver nanoparticles biosynthesis using a nonpathogenic soil bacterium Azospirillum brasilense. The conditions and parameters for synthesis of biogenic nanoparticles using A. brasilense vegetative cells, culture liquid, and homogeneous polyphenol oxidase preparations were analyzed. We have revealed the ranging effect of the incubation time, the concentration of silver ions, pH of the reaction mixture, and the concentration of metabolites, towards the production of colloidal silver nanoparticles with specified geometric parameters, high colloidal stability and relatively good monodispersity. The size, shape, and relative yield of electron-dense nanostructures were determined by transmission electron microscopy and dynamic light scattering; extinction spectra were recorded by UV-vis spectrophotometry. [ABSTRACT FROM AUTHOR]

The present study describes a novel method for green synthesis of silver nanoparticles using Cnidium monnieri (CM-AgNPs). Cnidium monnieri fruit is an excellent anti tinea drug that can be used externally to treat superficial fungal infections in the human body. The aqueous ethanolic extract of Cnidium monnieri fruit was prepared and employed in the synthesis of stable silver nanoparticles via biological reduction method. The synthesis conditions of CMAgNPs was systematically optimized using Box-Behnken design. CM-AgNPs were well characterized by UV-spectroscopy and X-ray powder diffraction (XRD), and it was confirmed that the synthesized particles were AgNPs. The possible functional groups required for the reduction and stabilization of CM-AgNPs in the extract were identified through FTIR spectrum. The size of CM-AgNPs structure was confirmed to be approximately 44.6 nm in polydisperse spherical shape through scanning electron microscopy (SEM), transmission electron microscopy (TEM), and laser dynamic light scattering (DLS). Further, the minimum inhibitory concentration 90% (MIC90) ratios values of Cm-AgNPs against Trichophyton rubrum (7 d), T. mentagrophytes (7 d) and Candida albicans (24 h) were 3.125, 3.125, and 0.78125 µg/mL, respectively, determined by the broth micro dilution method. Finally, the result was concluded that the synthesized AgNPs could be further evaluated in large scale as a potential human topical antifungal agent. [ABSTRACT FROM AUTHOR]

This study used opium sirup (OP) as reducing and stabilizing agent to improve the biological properties of silver nanoparticles (AgNPs) by green approach. XRD, UV–visible spectrum, ESEM, TEM, dynamic light scattering, FT-IR, density functional theory and Zeta potential techniques were employed to investigate the synthesis particles. Stable well-dispersed spherical AgNPs with a mean grain size of 4 nm were successfully synthesized. Our data revealed the enhanced anti-bacterial effects of Ag-opium at higher concentrations of OP against the human pathogens including Streptococcus mutants, Staphylococcus aureus, Klebsiella pneumonia, and E. coli. DPPH free radical scavenging assay showed the AgNPs and O can act as anti-oxidant as well as suppressor agents on the maintenance of DPPH radicals as a function of their dosages. Also, MTT assay was shown that the green synthesized AgNPs effects significantly increased the anti-proliferative with activities of prepared samples on MDA-MB-468 cells as a dose depended manner. [ABSTRACT FROM AUTHOR]

Green synthesis of silver nanoparticles (AgNPs) from aqueous silver nitrate has been achieved using an extract of Ferula communis leaf as a capping, reducing, and stabilizing agent. The formation and stability of the green synthesized silver nanoparticles in the colloidal solution were monitored by absorption measurements. Silver nanoparticles were characterized by different analyses such as X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and FT-IR spectroscopy. The average particle size of silver nanoparticles was determined by high-resolution transmission electron microscopy (HRTEM) and scanning electron microscopy (SEM) analyses. In this experiment, pregnant female mice were divided into four groups (G); G1 was the control and received phosphate-buffered saline, G2 received orally aqueous extract of F. communis leaf, G3 received orally AgNPs chemically prepared by NaBH4, and G4 received orally AgNPs prepared by aqueous extract of F. communis leaf. The diameter of AgNPs was 20 nm. AgNPs exhibited good catalytic reduction ability toward methyl orange in the presence of sodium borohydride with a rate constant of 2.95 x 10−4 s−1. The results revealed the occurrence of resorbed embryos in G2, G3, and G4 with different percentages. The livers of mothers and embryos at E14.5 in G2, G3, and G4 showed different levels of histopathological alteration and increase in GFAP and CTGF expressions compared with the control group. The study concluded that the oral administration of small-sized AgNPs (20 nm) prepared by Ferula extract had less toxicity than those prepared by the chemical method. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) were successfully synthesized using an extract derived from Arctium lappa leaves, serving as both a reducing agent and stabilizer. This method proved to be rapid, environmentally friendly, and feasible at room temperature. The synthesized AgNPs were subjected to UV-vis spectrophotometry analysis, revealing a distinct peak at 422 nm, confirming the presence of silver nanoparticles. The spherical morphology of these nanoparticles was determined through atomic force microscopy (AFM) and scanning electron microscopy (SEM), displaying an average diameter of 40 nm. Moreover, the AgNPs obtained from the A. lappa leaf extract showcased notable antifungal capabilities, effectively impeding the growth of Phytophthora infestans and Alternaria. This study successfully demonstrated the potential of A. lappa leaf extract as an efficient and eco-friendly medium for the synthesis of silver nanoparticles. These nanoparticles not only exhibited distinctive characteristics, as revealed by UV-vis spectrophotometry and microscopy techniques, but also displayed significant antifungal activity. [ABSTRACT FROM AUTHOR]

Background: Diabetes mellitus (DM) is a non-communicable, life-threatening syndrome that is present all over the world. The use of eco-friendly, cost-effective, and green-synthesised nanoparticles as a medicinal therapy in the treatment of DM is an attractive option. Objective: In the present study, silver nanoparticles (AI-AgNPs) were biosynthesized through the green synthesis method using Azadirachta indica seed extract to evaluate their anti-diabetic potentials. Methods: These nanoparticles were characterized by using UV-visible spectroscopy, Fourier transform infrared spectrophotometers (FTIR), scanning electron microscopy (SEM), DLS, and X-ray diffraction (XRD). The biosynthesized AI-AgNPs and crude extracts of Azadirachta indica seeds were evaluated for anti-diabetic potentials using glucose adsorption assays, glucose uptake by yeast cells assays, and alpha-amylase inhibitory assays. Results: Al-AgNPs showed the highest activity (75 ± 1.528%), while crude extract showed (63 ± 2.5%) glucose uptake by yeast at 80 µg/mL. In the glucose adsorption assay, the highest activity of Al-AgNPs was 10.65 ± 1.58%, while crude extract showed 8.32 ± 0.258% at 30 mM, whereas in the alpha-amylase assay, Al-AgNPs exhibited the maximum activity of 73.85 ± 1.114% and crude extract 65.85 ± 2.101% at 100 µg/mL. The assay results of AI-AgNPs and crude showed substantial dose-dependent activities. Further, anti-diabetic potentials were also investigated in streptozotocin-induced diabetic mice. Mice were administered with AI-AgNPs (10 to 40 mg/kg b.w) for 30 days. Conclusions: The results showed a considerable drop in blood sugar levels, including pancreatic and liver cell regeneration, demonstrating that AI-AgNPs have strong anti-diabetic potential. [ABSTRACT FROM AUTHOR]

In the present research, Livistona chinensis leaf extracts were utilized as reductants to bio-fabricate silver nanoparticles (LC-AgNPs) and this was followed by the evaluation of their antioxidant, antibacterial, and anticancer potential. Multiple parameters were optimized for the formation and fidelity of LC-AgNPs. The color shift of the reaction mixture from yellow to dark brown confirmed the LC-AgNPs formation. UV/VIS spectroscopy exhibited a surface plasmon resonance (SPR) band at 436 nm. The Fourier transform infrared (FTIR) spectroscopy spectrum depicted phytochemicals in the plant extract acting as bio-reducers for LC-AgNPs synthesis. The XRD pattern confirmed the presence of LC-AgNPs by showing peaks corresponding to 2θ angle at 8.24° (111), 38.16° (200), 44.20° (220), and 64.72° (311). Zetasizer analysis exhibited size distribution by intensity of LC-AgNPs with a mean value of 255.7 d. nm. Moreover, the zeta potential indicated that the AgNPs synthesized were stable. The irregular shape of LC-AgNPs with a mean average of 38.46 ± 0.26 nm was found by scanning electron microscopy. Furthermore, the antioxidant potential of LC-AgNPs was examined using a DPPH assay and was calculated to be higher in LC-AgNPs than in leaf extracts. The calculated IC50 values of the LC-AgNPs and plant extract are 85.01 ± 0.17 and 209.44 ± 0.24, respectively. The antibacterial activity of LC-AgNPs was investigated against Escherichia coli, Pseudomonas aeruginosa, and Bacillus subtilis as well as Staphylococcus aureus, and maximum potential was observed after 24 h against P. aeruginosa. Moreover, LC-AgNPs exhibited maximum anticancer potential against TPC1 cell lines compared to the plant extract. The findings suggested that LC-AgNPs could be used as antioxidant, antibacterial, and anticancer agents for the cure of free-radical-oriented bacterial and oncogenic diseases. [ABSTRACT FROM AUTHOR]

In this study, we have developed an environment friendly and novel approach for the synthesis of silver nanoparticles utilising plumeria pudica leaf extract. In this technique, the leaf extract was employed as both a reducing agent for the reduction of a silver nitrate (AgNO3) solution and a capping agent, leading to the synthesis of silver nanoparticles (Ag NPs). The outcomes of these analyses revealed an average particle size of ∼19 nm as determined by SEM, while XRD measurements indicated a crystalline domain size of ∼12 nm and a lattice parameter of approximately 4.087467 Å. Furthermore, the anti-cancer potential of the synthesised silver nanoparticles was evaluated, unveiling an IC50 value of around 28 µM. This suggests that the introduced silver nanoparticles may have triggered apoptosis, consequently inducing cell death. These findings underscore the potential of utilising environmentally benign silver nanoparticles in lung cancer chemotherapy. [ABSTRACT FROM AUTHOR]

Green synthesis of silver nanoparticles (AgNPs) has attracted substantial interest and achievement due to their environmental friendliness, ease of manipulation, and potential for large-scale production. By using aqueous Camellia sinensis leaf extract, suspensions of AgNPs, which possess photocatalytic and biological activity, were successfully synthesized in this study. The reduction of silver ions to AgNPs was visually inspected via the colour of the reaction mixture, which was altered from pale yellow to reddish brown. The methods of characterization of the as-synthesized AgNPs were performed using Ultraviolet-Visible spectroscopy (UV-Vis), dynamic light scattering technique (DLS), and X-ray diffraction analysis (XRD). The surface plasmon resonance bands of AgNPs at 420-430 nm in UV-Vis spectra indicated the presence of silver particles at the nanoscale. The size of AgNPs was determined by DLS, ranging from 25 nm to 40 nm. XRD analysis showed that AgNPs were highly pure and crystalline. The antibacterial activity of AgNPs against Gram-positive and Gram-negative bacterial strains, including Staphylococcus aureus and Escherichia coli, respectively, was demonstrated by the disc diffusion method. The examination of the photocatalytic activity of AgNPs was conducted through methylene blue (MB) degrading experiments, and the MB degrading performance was approximately 95% within 72 h under sunlight. [ABSTRACT FROM AUTHOR]

Advances in nanotechnology have contributed to many innovative approaches in the forensic sciences, including the development of new techniques and protocols for latent fingermark detection. Among other nanomaterials, metal-based nanoparticles have been explored as suitable developers for fingermarks present on surfaces that challenge traditionally established methods. The present study explored, for the first time in the forensic science literature, the application of greenly synthesized silver nanoparticles (AgNPs) for latent fingermark surface-assisted laser desorption/ionization mass spectrometry (SALDI MS) analysis. A leaf extract of a native plant from the Cerrado biome was used for green synthesis of the AgNPs, and their hydrodynamic diameter, polydispersity index (PdI), and Zeta potential values were evaluated. Latent fingermarks were produced by three distinct donors and treated with α-CHCA matrix or AgNP suspension and were further investigated using commercial matrix assisted laser desorption/ionization (MALDI)-TOF MS equipment in the m/z range of 100–1000. Characterization results of the AgNPs indicated an average hydrodynamic diameter of 25.94 ± 0.30 nm, a PdI of 0.659 ± 0.085, and a Zeta potential of −33.4 ± 2.6 mV. The silver ions detected showed a relative intensity at least 20× higher for greenly synthesized AgNPs than for AgNO3 suspension, which may be advantageous for the detection of molecular species, especially olefins, present in forensic traces. The AgNP-based SALDI MS approach for the analysis of latent fingermarks showed intense ions at m/z 106.9, 215.8, and 322.7, referring to silver cation species that have been reported as important internal calibrants. The detection of components from endogenous and exogenous sources in latent fingermarks was achieved using the present approach. Greenly synthesized AgNPs may offer a new cost-effective, eco-friendly, and easily scaled up method for application in the chemical analysis of fingermarks. [ABSTRACT FROM AUTHOR]

In the current study, using Cleistocalyx operculatus bud extracts to synthesize silver nanoparticles is considered a novel, eco-friendly, and low-priced process that advances chemical and physical methods. C. operculatus bud extracts played a dual part in reducing and stabilizing silver nanoparticles. The formation of silver nanoparticles was recognized on UV–Vis spectra at an absorption maximum of 432 nm. Transmission electron microscopy images detected the quasi-spherical nanoparticle shape with an average size of 26.2 nm corresponding with water extract and 27.5 nm synthesized by ethanol–water extract. The obtained silver nanoparticles had moderate stability with zeta potential ranging from − 15.4 to − 38.4 mV. The phase purity of the bio-synthesized materials was confirmed by an X-ray diffraction pattern. The Fourier transform infrared analysis demonstrated hydroxyl groups acting as stabilizing agents in the extract. Silver nanoparticles synthesized from ethanol–water extract exhibited higher antibacterial and anticancer activity than nanomaterials prepared with water extract. Positive-gram bacteria (Bacillus subtilis, Lactobacillus fermentum, and Staphylococcus aureus, negative-gram bacteria (Escherichia coli, Pseudomonas aeruginosa, and Salmonella enterica), and cancer cell lines (lung cancer A549, hepatic cancer Hep-G2, epidermal carcinoma KB, and breast cancer MCF-7) were both inhibited by the nanoparticles synthesized with ethanol–water extract. [ABSTRACT FROM AUTHOR]

In this work, we aimed to analyze the impact of extracts prepared from dried Lavandula angustifolia (lavender) flowers and leaves on the synthesis of silver nanoparticles (AgNPs) (wherein the shape and size of AgNPs and the efficiency of the process were analyzed) and to prove the possibility of transferring the AgNPs' properties into a polymer matrix. An ex situ method was used to incorporate AgNPs and prepare polymer matrix composite (PVP-AgNPs) films (via casting) and fibers (via electrospinning). We used UV-vis absorption spectrophotometry, Fourier Transform Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM), and Scanning Electron Microscopy (SEM) to analyze and characterize the AgNPs and prepared composites. The results of FTIR analysis confirmed the presence of phytochemicals that can reduce silver ions from Ag+ to Ag0 in both extracts. The presence of spherical nanoparticles was confirmed via TEM regardless of the type of extract used. However, leaf extract caused the formation of AgNPs with a narrower size interval (an average size of 20 nm), and with higher efficiency, compared to the nanoparticles prepared using the flower extract. The nanoparticles prepared using the leaf extract were then incorporated into the polymer matrix, and thin polymer composite films and fibers were successfully prepared. The anti-biofilm activity of AgNPs colloids and prepared polymer nanocomposites against green algae Chlorella kessleri was studied. The anti-biofilm properties of the AgNPs were proved, along with the efficient transfer of their toxic properties into nontoxic polymer. [ABSTRACT FROM AUTHOR]

In this study, cotton fabrics are coated with green hydrothermally synthesized AgNPs over coated with polymethyl methacrylate (PMMA) using a two-step dip-coating technique to impart antibacterial activity. The synthesized AgNPs are characterized using XRD, SEM with EDX mapping, TEM, XPS, and UV-Vis spectrometer. XRD analysis confirmed the crystalline nature of AgNPs, while FESEM images and EDX spectra showed the poly-dispersed nature of particles with irregular shapes and high agglomeration due to the presence of phytochemicals. TEM images showed that the particles are close to each other but not diffused. XPS analysis of AgNPs elucidated the chemical states of elements present, and UV-Vis analysis showed the absorption maximum at 440 nm. Antibacterial activity against gram-negative E. coli and gram-positive S. epidermidis and methicillin-resistant Staphylococcus aureus bacterial strains is evaluated using both optical density and well diffusion techniques, demonstrating that AgNPs display dose-dependent antibacterial activity against the tested strains. The antibacterial efficacy of AgNPs is dependent on the quantity of Ag moiety and the type of bacterial strain. The study also showed that AgNPs/PMMA-coated cotton fabrics exhibited a roughened surface with embedded nano-sized particles, and EDX spectra confirmed the presence of Ag moiety on the surface of cotton fabric treated with AgNPs/PMMA. The antibacterial activity of AgNPs/PMMA-coated cotton fabric is efficient and durable when compared to AgNPs-coated cotton fabric, as PMMA acted as the binder. Thus, a coating mixture is developed that could impart stable antibacterial activity to cotton fabric. [ABSTRACT FROM AUTHOR]

The investigation of using medicinal plants for the production and application of silver nanoparticles (AgNPs) has attracted growing research interest. In this study, AgNPs are synthesized from the stem barks of the Pyrus pashia medicinal plant using a biosynthetic strategy. The reaction conditions were optimized under ambient conditions, including concentration, temperature, time, and pH, and various techniques were employed, such as UVvisible, FTIR, XRD, FESEM, and TEM, to characterize the synthesized AgNPs. The AgNPs produced through this biosynthesis method were found to be spherical and polydispersed, with an average size of 23.92 ± 7.04 nm. The synthesized AgNPs demonstrated an enhanced DPPH free radical scavenging capacity compared to the aqueous extract, with IC50 values of 10.67 ± 0.05 µg/mL and 13.66 ± 0.35 µg/mL, respectively. In the agar well diffusion method, the synthesized AgNPs showed higher antibacterial activity than that of the extract against Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 25923), Enterococcus faecalis (ATCC 29212), Salmonella typhi (ATCC 14028), and Shigella sonnei (ATCC 25931). Based on these findings, the study suggests that green synthesized AgNPs from P. pashia could be used for biomedical applications. [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]

The era of increasing bacterial antibiotic resistance requires new approaches to fight infections. With this purpose, silver-based nanomaterials are a reality in some fields and promise new developments. We report the green synthesis of silver nanoparticles (AgNPs) using culture broths from a microalga. Broths from two media, with different compositions and pHs and sampled at two growth phases, produced eight AgNP types. Nanoparticles harvested after several synthesis periods showed differences in antibacterial activity and stability. Moreover, an evaluation of the broths for several consecutive syntheses did not find relevant kinetics or activity differences until the third round. Physicochemical characteristics of the AgNPs (core and hydrodynamic sizes, Z-potential, crystallinity, and corona composition) were determined, observing differences depending on the broths used. AgNPs showed good antibacterial activity at concentrations producing no or low cytotoxicity on cultured eukaryotic cells. All the AgNPs had high levels of synergy against Escherichia coli and Staphylococcus aureus with the classic antibiotics streptomycin and kanamycin, but with ampicillin only against S. aureus and tetracycline against E. coli. Differences in the synergy levels were also dependent on the types of AgNPs. We also found that, for some AgNPs, the killing of bacteria started before the massive accumulation of ROS. [ABSTRACT FROM AUTHOR]

Chromium (Cr) is one of the hazardous heavy metals that is naturally carcinogenic and causes various health problems. Metallic nanoparticles such as silver and copper nanoparticles (Ag NPs and Cu NPs) have gained great attention because of their unique chemical, physical, and biological attributes, serving diverse and significant role in various useful and sustainable applications. In the present study, both of these NPs were synthesized by green method in which Azadirachta indica plant extract was used. These nanoparticles were characterized by using advanced instrumental techniques such as Fourier transmission infrared (FTIR), X-ray diffraction (XRD), scanning electron microscope attached with energy-dispersive spectroscopy (SEM-EDS), and elemental mapping. These environmentally friendly nanoparticles were utilized for the batch removal of Cr from the wastewater. For analysis of adsorption behaviour, a range of kinetic isotherm models (Freundlich, Temkin, Dubinin, and Langmuir) and kinetic models (pseudo-first-order and pseudo-second-order) were used for the Cu-NPs and Ag-NPs. Cu NPs exhibited the highest Cr removal efficiency (96%) within a contact time of 10–15 min, closely followed by Ag NPs which achieved a removal efficiency of 94% under the similar conditions. These optimal outcomes were observed at a sorbent dose of 0.5 g/L for Ag NPs and 0.7 g/L for Cu NPs. After effectively capturing Cr using these nanoparticles, the sorbates were examined through SEM-EDX analysis to observe how much Cr metal was attached to the nanoparticles, potentially for future use. The analysis found that Ag-NPs captured 18% of Cr, while Cu-NPs captured 12% from the aqueous solution. More precise experimental conditions are needed for higher Cr removal from wastewater and determination of the best conditions for industrial-level Cr reuse. Although nanomaterial exhibit high efficiency and selectivity for Cr removal and recovery from wastewater, more research is necessary to optimize their synthesis and performance for industrial-scale applications and develop efficient methods for Cr removal and recovery. [ABSTRACT FROM AUTHOR]

Objectives: Disinfection of alginate impression materials is a mandatory step to prevent cross-infection in dental clinics. However, alginate disinfection methods are time-consuming and exert a negative impact on accuracy and mechanical properties. Thus, this study aimed to prepare disinfecting agents (CHX and AgNO3) and silver nanoparticles reduced by a natural plant extract to produce a self-disinfecting dental alginate. Methods: Conventional alginate impression material was used in this study. Silver nitrate (0.2% AgNO3 group) and chlorohexidine (0.2% CHX group) solutions were prepared using distilled water, and these solutions were later employed for alginate preparation. Moreover, a 90% aqueous plant extract was prepared from Boswellia sacra (BS) oleoresin and used to reduce silver nitrate to form silver nanoparticles that were incorporated in the dental alginate preparation (BS+AgNPs group). The plant extract was characterized by gas chromatography/mass spectrometry (GC/MS) analysis while green-synthesized silver nanoparticles (AgNPs) were characterized by UV-visible (UV–vis) spectroscopy and scanning electron microscopy (SEM). An agar disc diffusion assay was used to test the antimicrobial activity against Candida albicans, Streptococcus mutans, Escherichia coli, methicillin-resistant and susceptible Staphylococcus aureus strains, and Micrococcus luteus. Agar plates were incubated at 37 ± 1 °C for 24 h to allow microbial growth. Diameters of the circular inhibition zones formed around each specimen were measured digitally by using ImageJ software. Results: Chemical analysis of the plant extract revealed the presence of 41 volatile and semi-volatile active compounds. UV–Vis spectrophotometry, SEM, and EDX confirmed the formation of spherical silver nanoparticles using the BS extract. CHX, AgNO3, and the BS+AgNPs modified groups showed significantly larger inhibition zones than the control group against all tested strains. BS+AgNPs and CHX groups showed comparable efficacy against all tested strains except for Staphylococcus aureus, where the CHX-modified alginate had a significantly higher effect. Conclusions and clinical relevance: CHX, silver nitrate, and biosynthesized silver nanoparticles could be promising inexpensive potential candidates for the preparation of a self-disinfecting alginate impression material without affecting its performance. Green synthesis of metal nanoparticles using Boswellia sacra extract could be a very safe, efficient, and nontoxic way with the additional advantage of a synergistic action between metal ions and the phytotherapeutic agents of the plant extract. [ABSTRACT FROM AUTHOR]

The growing popularity of silver nanoparticles in the field of nanotechnology has created the necessity of developing new sustainable synthesis methods. This study presents a new green in situ functionalization method of melamine foams with silver nanoparticles. The synthesis pathway and the influence of the processing parameters are optimized to phase out 100% of polluting and dangerous solvents while maximizing silver transfer. A deep study of the morphological and chemical changes of the synthesized silver nanoparticles successfully demonstrated that water can be used as the only solvent for obtaining active melamine foams with potential application in multiple fields. Results showed that rising reaction temperatures from environmental to mild conditions (40 °C and 60 °C) is crucial for obtaining high functionalization yields with this green method. Following the optimum fabrication conditions using only water, highly functionalized melamine foams showed a great amount of ultrafine silver nanoparticles distributed over the porous structure. [ABSTRACT FROM AUTHOR]

This study reports the reduction of AgNO3 using green-synthesized carbon dots (CDs) derived from the leaf extract of Datura metel without the aid of any chemical-reducing agent. The CDs act as both reducing and stabilizing agent to synthesize CDs-functionalized silver nanoparticles (Ag/CDs) and are employed for surface-enhanced Raman spectroscopy (SERS)-based detection of thiram fungicide. The formation of Ag/CDs is confirmed with UV–Vis absorption spectroscopy and Raman spectroscopy. The synthesized Ag/CDs exhibit high stability and the fabricated SERS substrate exhibited a detection range of 10–3 to 10–8 M with a corresponding correlation coefficient of 0.98. The obtained minimum detection limit of thiram is 10–8 M with an enhancement factor of 1.3 × 105 which is much lower than the maximum allowed residual limit of 7 ppm. This study emphasizes the green route to synthesize CDs-functionalized stable AgNPs for the SERS-based detection of thiram fungicide and explained the sensing mechanism. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs) have been synthesized using Rhoeo discolor leaf extract as a reducing and stabilizing agent. AgNPs were synthesized by adding silver nitrate to the extract of Rhoeo discolor and incubating it in a boiling water bath. The change in color of the mixture from clear to yellow indicated AgNPs formation. The synthesized AgNPs were spherical and showed an absorption peak at around 410-420 nm. The size of particles was distributed from 3 to 18 nm with an average size of 8 ± 2 nm, and the polydispersity index was 0.185. The stability test showed that synthesized AgNPs were stable for three months of storage at ambient temperature. The extract of Rhoeo discolor were responsible for reducing silver ion and stabilizing the synthesized AgNPs. [ABSTRACT FROM AUTHOR]

There are numerous green methods for synthesizing silver nanoparticles using plant extracts such as leaves, flowers, stems, and fruit extracts. However, most of those synthesized have weaknesses such as slow reduction and inefficient time. This study used a microwave to accelerate the reduction process of Ag+ ions into Ag0 nanoparticles using an aqueous extract of Citrus sinensis peels. A heating time of 5 minutes produces silver nanoparticles in optimal condition with a color change from yellow to reddish brown. According to UV-Vis, silver nanoparticles at power 100 W and 300 W show peaks at 404 nm and 406 nm. FTIR indicates that phytochemical compounds are involved in the reduction of nanoparticles. XRD shows silver nanoparticles are FCC crystalline. TEM reveals that power 100 W yields an average diameter of 12 nm while 300 W shows a smaller diameter of 5 nm. [ABSTRACT FROM AUTHOR]

Bimetallic (Ag-Au/Au-Ag) nanoparticles have been synthesized using Litchi chinesis leaf extract and characterised using UV-visible spectroscopy, dynamic light scattering (DLS), zeta potential and transmission electron microscopy (TEM). The hydrodynamic size of Ag-Au/Au-Ag NPs are found to be 83 nm/90 nm, respectively, by DLS techinque. The catalytic capability of green synthesised silver, gold and bimetallic(Ag-Au) nanoparticles is described in this study by choosing the degradation of methylene blue, as a model dye. [ABSTRACT FROM AUTHOR]

Green synthesis offers a superior alternative to traditional methods for producing metal and metal oxide nanoparticles. This approach is not only benign and safe but also cost-effective, scalable, and straightforward, operating under ambient conditions. Notable metals and metal oxide nanoparticles, such as manganese oxides, iron oxides, silver, and gold, have been produced using various bio-reductants derived from plant extracts. These biological agents not only expedite the reduction process but also stabilize the nanoparticles, serving dual roles as reducing and capping agents. This review presents the green synthesis of nanoparticles (NPs) obtained from biogenic wastes and plant extracts. The green-synthesized nanostructured MnO2 nanoparticles are evaluated as a potential photocatalyst for water treatment and as an electrode material in lithium-ion batteries and supercapacitors. The green-derived iron oxide nanoparticles are examined as promising antioxidant, anti-inflammatory, and anti-diabetic agents. Additionally, this review discusses the green synthesis of precious metal nanoparticles, specifically silver (Ag NPs) and gold (Au NPs), highlighting their potential medical applications in areas like antiviral treatments and cancer therapy. [ABSTRACT FROM AUTHOR]

Without a doubt, cancer and its negative impact on human health have created many hurdles for people across the world since conventional approaches have not offered a reliable ability in the eradication of cancer. As a result, finding novel approaches, like using bimodal nanoparticles as a potential nanocarrier in molecular imaging and cancer therapy, is remarkably required these days. In the present study, ex-situ (Ge) and in-situ (Gi) green synthesized silver (Ag) nanoparticles entrapped in metal-organic framework nanocomposites (NMOF) coated with folic acid (FA) targeted chitosan (CS) was successfully developed as a novel bifunctional nanocarrier for detection and treatment of colon cancer cells. Then nanocarriers, such as NMOF–CS–FA, Ge–Ag@NMOF–CS–FA, Gi-Ag@NMOF–CS–FA, and C–Ag@NMOF–CS–FA, were characterized via FT-IR, DLS, SERS, TEM, and SEM and results have potentially confirmed the quality and quantity of synthesized nanocomposites. The hydrodynamic diameters of NMOF-CS, Ge–Ag@NMOF-CS, Gi-Ag@NMOF-CS, and C–Ag@NMOF-CS specimens were measured at around 99.7 ± 10 nm, 110 ± 10 nm, 118 ± 10 nm, 115 ± 10 nm, respectively. Also, the PDI values less than 0.2 confirm the reliable distribution of these nanocomposites. Afterward, the cell viability assay was conducted on HCT116 and HGF cell lines for evaluating biocompatibility and targeting efficiency of nanocomposites; FA functionalized nanocomposites have intensively indicated better performance in cancer cells targeting and their inhibition, and IC50 was attained for 10 ng/mL of Ge–Ag@NMOF–CS–FA while non-targeted nanocarriers did not have toxicity more than 20 % on HCT116 colon cancer cells. Moreover, according to the results, the cell viability of HGF normal cells was at least 85 % after being exposed to different concentrations of nanocomposites for 24 h. This indicates that the synthesized nanocomposites do not have significant toxic effects on normal cells. The results indicate that this novel nanocomposite has the potential to effectively deliver drugs to cancer cells.

Green synthesis of silver nanoparticles (AgNPs) employing agricultural wastes as plant extracts to improve environmental benignity and also economic value added is the highlight of this research. The mature pseudostem of Alpinia nigra is an unbeneficial raw material discarded from several food ingredients and medicinal formulas. Therefore, this research focused on condition optimization for AgNP synthesis with ecofriendly techniques using A. nigra mature-pseudostem extracts and evaluation of their antioxidant, antibacterial activities, and toxicity with brine shrimp lethality assay (BSLA). The optimal reaction conditions were achieved by using 5 mM silver nitrate (AgNO3) solution with a volume ratio of 2:8 for the extract to AgNO3 at pH 12 under room temperature. The morphology and crystalline phase of the generated AgNPs were characterized using UV–visible spectrophotometry, field emission-scanning electron microscope (FE-SEM), energy dispersive X-ray, X-ray diffraction, and Fourier transform-infrared (FTIR) techniques. The FE-SEM analysis exposed spherical shapes with an average diameter of approximately 49 nm. The XRD analysis indicated their face center cubic structure, and the FTIR spectra confirmed that phytochemicals from A. nigra extract promoted the synthesis of AgNPs. In particular, the biosynthesized AgNPs presented potential antibacterial activity against both Staphylococcus aureus and Escherichia coli and effective antioxidant capacity using the DPPH radical scavenging assay. Additionally, non-toxic desired AgNPs were confirmed with BSLA.

Silver nanoparticles (AgNPs), widely recognized for their nanoscale geometric size and unique properties, such as large specific surface area, high permeability, and high safety, were synthesized using the endophytic fungus Penicillium polonicum PG21 through a green approach. Four key synthesis factors—48 h, 45 °C, pH 9.0, and 80 mM AgNPs concentration—were optimized. Characterization via ultraviolet–visible spectroscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, and X-ray diffraction revealed the AgNPs as approximately 3–25 nm spherical particles with numerous functional groups ensuring stability. AgNPs were tested against various fungal and bacterial plant pathogens, including Botrytis cinerea (EB-1), Alternaria alternata (EB-2, EB-3), Fusarium solani (RG-1), Williamsia serinedens (SL-1), Sphingopyxis macrogoltabida (SL-2), Bacillus velezensis (SL-3), and Pseudomonas mediterranea (SL-4), causing agricultural challenges. PG21-synthesized AgNPs exhibited inhibition rates against all tested fungi, with 60 μg/mL AgNPs demonstrating optimal inhibition rates. Notably, EB-1 experienced a significant growth inhibition, reaching an inhibition rate reached of 74.22 ± 1.54%. Conversely, RG-1 exhibited the smallest inhibitory effect at 48.13 ± 0.92%. The effect of AgNPs on safflower seed germination and growth revealed notable increases in shoot length, fresh weight, stem length, and number of lateral roots—1.4, 1.4, 1.33, and 10.67 times higher than the control, respectively, at an AgNPs concentration of 80 μg/mL. In conclusion, green-synthesized AgNPs demonstrate pathogen toxicity, showcasing potential applications in disease management for industrial crops and promoting plant growth.

Biosynthesized nanoparticles are receiving attention because of naturally existing secondary metabolites from plants that support green synthesis and their biological applications. Hence, the Objective of this paper as to biosynthesize and characterize silver nano-composites of Enantia chlorantha extracts using appropriate standard techniques. The results of the FTIR research revealed significant heterogeneity in chemical shifts among the functional groups, indicating changes in chemical surroundings. Furthermore, the GC-MS analysis showed that the extract and Ec-AgNPs had different numbers of compound peaks: the extract had 28 peaks, while Ec-AgNPs had 32 peaks. Ec-AgNPs showed more antibacterial activity than the extract, although having equal phytochemical contents, suggesting their potential for medicinal uses. The importance of using plant extracts in green synthesis techniques to produce nanoparticles and their potential biological uses is highlighted by this study.