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Using extracts from herbs for silver nanoparticle synthesis is attracting attention for its anticancer activity. Ardisia gigantifolia is a herb used in traditional Chinese medicine for treating stomach ailments, and some compounds isolated from this plant exhibit the inhibitory activity against different cancer cells. However, the synthesis of silver nanoparticle using extract of Ardisia gigantiflia leaves and their anti-cancer activity was not reported. In this report, the green synthesized silver nanoparticles using Ardisia gigantiflia extract (Arg-AgNPs) has average diameter of 6 nm with functional groups including O–H, C–H, and C O founded on the surface of these nanoparticles. The viability assays results revealed Arg-AgNPs reduced gastric cancer cell proliferation in a dose-dependent manner, with IC 50 values of 1.37 and 0.65 μg/mL for AGS cells and 1.03 and 0.96 μg/mL for MKN45 cells. Arg-AgNPs caused cell cycle arrest at the G0/G1 phase and suppressed cell migration. Additionally, Arg-AgNPs significantly increased the percentage of senescent cells and promoted overproduction of reactive oxygen species (ROS) compared to the control. Thus, this study indicates that Arg-AgNPs can be considered as a promising candidate against human gastric cancer cells. • Arg-AgNPs were characterized by UV-Vis, XRD, TEM and FTIR. • Arg-AgNPs reduce cell viability and cause cell cycle arrest at G0/G1 phase in gastric cancer. • Arg-AgNPs reduce cell migration ability and induce cellular senescence in gastric cancer. • Arg-AgNPs promote overproduction of ROS in gastric cancer. [ABSTRACT FROM AUTHOR]

Nanotechnology has become the focus of scientific research due to its widespread and effective use. Silver nanoparticles (AgNPs) were produced utilizing Stachys spectabilis, and their antioxidant effect and catalytic degradation of methylene blue were investigated. The structure of ss-AgNPs was clarified by spectroscopy. FTIR demonstrated the possible functional group responsible for reducing agents. The absorption at 498 nm in the UV–Vis measurement verified the nanoparticle structure. XRD measurement demonstrated the nanoparticles to be face-centered cubic crystalline structures. TEM image proved the nanoparticles as spherical, and the size was determined as 10.8 nm. The intense signals at 2.8–3.5 keV in EDX confirmed desired product. The observation of zeta potential at −12.8 mV indicated the stability of nanoparticles. The nanoparticles can degrade the methylene blue with 54% at 40 h. The antioxidant effect of extract and nanoparticles was performed by ABTS radical cation, DPPH free radical scavenging, and FRAP assay. Nanoparticles revealed excellent ABTS activity (4.42 ± 0.10) in comparison to the standard BHT (7.12 ± 0.10). ss-AgNPs may be a promising agent for the pharmacy. • Silver nanoparticles were synthesized using Stachys spectabilis leaves. • UV–Vis, FTIR, XRD, TEM, EDX were used for elucidation of nanoparticles. • Nanoparticles displayed the outstanding antioxidant activity. • Nanoparticles synthesized from this plant can be used for clean technology. • Nanoparticles could be a promising agent for pharmaceutical industry. [ABSTRACT FROM AUTHOR]

Therapeutic management of mastitis faces significant challenges due to multidrug resistance. In the present study, multi-drug-resistant (MDR) Staphylococcus spp , Klebsiella pneumoniae, and Escherichia coli were isolated from bovine clinical mastitis cases and the phenotypic and genotypic multidrug resistance profiling was carried out. Silver nanoparticles (AgNPs) were biosynthesized using Ocimum sanctum leaf extracts and characterized via UV Vis absorption, Fourier Transform Infrared Spectroscopy, X-ray diffraction studies, Energy dispersive spectroscopy and Electron Microscopy. The determined minimum inhibitory concentration and minimum bactericidal concentration of the AgNPs against the recovered MDR isolates were 62.5 μg/ml and 125 μg/ml respectively. At a concentration of 50 μg/ml, the AgNPs demonstrated biofilm inhibitory activities of 80.35 % for MDR E. coli , 71.29 % for S. aureus and 60.18 % for MDR K. pneumoniae. Post-treatment observations revealed notable differences in biofilm formation across bacterial isolates. Furthermore, AgNP treatment led to significant downregulation of expression of the efflux pump genes acrB , acrE , acrF , and emrB in Gram-negative isolates and norB in Staphylococci isolates. This research underscores the potential for the development of an eco-friendly antimicrobial alternative in the form of green synthesized silver nanoparticles to combat drug resistance offering potential antibiofilm and efflux pump inhibitory activities. [Display omitted] • Multidrug resistant (MDR) Staphylococci, Klebsiella pneumoniae and Escherichia coli were isolated from clinical mastitis cases. • The phenotypic and genotypic multidrug resistance profiling was carried out. • Synthesized silver nanoparticles using Ocimum sanctum leaf extract as a reducing and capping agent. • Characterized the AgNPs using UV–vis spectroscopy, FTIR, XRD, SEM -EDAX and TEM. • They exhibited antimicrobial, antibiofilm and efflux pump inhibitory activity in multidrug resistant bacterial isolates. • Green synthesized silver nanoparticles are suitable candidates for combating multidrug resistant bacterial organisms. [ABSTRACT FROM AUTHOR]

• AgNPs thin film and AgNPs powder as a saturable absorber (SA) for Q-switched pulse generation. • AgNPs thin film demonstrates higher repetition rate, shorter pulse width, and lower pulse energy compared to AgNPs powder. • AgNPs thin film shows good stability, highlighting the influence of physical form on pulse characteristics and its potential for various applications. We successfully investigate the generation of Q-switched pulses utilizing two distinct forms of silver nanoparticles (AgNPs): AgNPs thin film and AgNPs powder. Employing a green synthesis approach with AgNO3 and Oolong tea extract, AgNPs were fabricated as saturable absorbers (SAs) for Q-switching. The AgNPs thin film SA exhibited a remarkable repetition rate of 79.53 kHz, coupled with a pulse width of 2.38 µs and a pulse energy of 1.08 nJ. In contrast, AgNPs powder achieved a repetition rate of 40.53 kHz, a pulse width of 3.33 µs, and a pulse energy of 2.03 nJ. Notably, the AgNPs thin film demonstrated superior stability with a signal-to-noise ratio (SNR) of 55.07 dB compared to the powder's SNR of 50.65 dB. These findings underscore the significant impact of the physical form of saturable absorbers on pulse characteristics, offering promising avenues for diverse applications in telecommunication, optical fiber sensors, and material processing. The novelty lies in comparing different physical forms of AgNPs as saturable absorbers, revealing distinct performance metrics and highlighting their potential for various technological applications. [ABSTRACT FROM AUTHOR]

Bacterial biofilms pose a significant threat to healthcare due to their recalcitrance to antibiotics and disinfectants. This study explores the anti-biofilm potential of Bacillus licheniformis cell-free culture supernatant (CFS) and its derived silver nanoparticles (bSNPs) against Staphylococcus aureus and Pseudomonas aeruginosa. The CFS exhibited potent anti-biofilm activity against both bacterial species, even at low concentrations, while devoid of significant bactericidal effects, mitigating resistance risks. Characterization studies revealed the non-proteinaceous nature and thermal stability of the CFS's anti-biofilm agent, suggesting a robust and heat-resistant structure. Green synthesis of bSNPs from CFS resulted in nanoparticles with significant anti-biofilm properties, particularly against P. aeruginosa , indicating differences in susceptibility between the bacterial species. Epifluorescence microscopy confirmed bSNPs' ability to inhibit and partially disrupt biofilm formation without inducing cellular lysis. The study highlights the potential of B. licheniformis CFS and bSNPs as promising biofilm control agents, offering insights into their mechanisms of action and broad-spectrum efficacy. Further research elucidating the underlying molecular mechanisms and identifying specific bioactive compounds is warranted for the translation of these findings into clinically relevant applications for combating biofilm-associated infections. • B. licheniformis CFS disrupts biofilms at low concentrations. • Non-protein, heat-stable biofilm agent found in B. licheniformis CFS. • Biogenic silver nanoparticles (bSNPs) showed broad-spectrum anti-biofilm activity. • bSNPs inhibit & partially disrupt biofilms without cell lysis. • B. licheniformis & bSNPs hold promise for biofilm control. [ABSTRACT FROM AUTHOR]

Fish-borne pathogens such as A. hydrophila and F. aquidurense are the most resistant strains in pisciculture farming. Removing the aforementioned pathogens without antibiotics presents a formidable challenge. To overcome this problem, silver nanoparticles (AgNPs) are synthesized using silver nitrate, water medium, and as an AzadirachtaIndica leaf extract via the green synthesis route. X-ray diffraction (XRD) pattern results authenticate the synthesized material is the face-centered cubic structure of silver. The optical absorption edge of the synthesized product was found at the wavelength of 440 nm from the UV–visible spectra, which is confirmed to relate to the Surface Plasmon Resonance peaks of silver particles. In addition, the optical band gap value of the synthesized Ag sample is measured to be 2.81 eV from the obtained optical absorption spectra. EDX spectrum of the synthesized product also supports confirming the silver particle formation. The FT-IR spectra of the neem extract and silver nanoparticles showed their characteristic functional groups, respectively. The presence of bands between 1000 cm−1 to 500 cm−1 indicates to the formation of silver particles. Spherical particles appeared in the synthesized Ag using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The particle size of Ag NPs was measured as 40 nm and 62 ± 10 nm by TEM and Dynamic Light Scattering (DLS). The zeta potential was also measured as −12 mV showing the synthesized sample's stable nature. Using the DPPH assay, synthesized AgNPs were taken along with the various concentrations of ascorbic acid (20, 40, 60, 80, and 100 μg/mL) to examine the free radical scavenging activity (RSA). RSA value is higher (84 ± 2 %) for synthesized AgNPs at higher concentration (100 μg/mL) than 21 ± 2 % at low concentration (100 μg/mL). The antimicrobial efficacy of the AgNPs against A. hydrophila and F. aquidurense was performed through the agar diffusion method and its results showed the inhibitory zones of the F.aquidurense and A. hydrophila were measured as 25 ± 3 mm, and 28 ± 4 mm respectively. The synthesized Ag particles showed excellent antimicrobial and antioxidant properties confirmed by antimicrobial and DPPH experiments. It implies that the green synthesized silver nanoparticles could be a good alternative for antibiotics in aquaculture farms. The exposure of low concentrations of silver nanoparticles to zebrafish and brine shrimp does not affect the viability and morphology. The exposure of silver nanoparticles in the fisheries in optimized concentration and time could control the fish-borne pathogens without antibiotics. [Display omitted] • Silver nanoparticles are prepared using AzadirachtaIndica leaf extract assisted via green synthesis route. • Tracing elements, morphology, zeta potential and functional groups of the synthesized material were tested by EDX, SEM/TEM, DLS, and FT-IR analysis. • The synthesized Ag particles showed excellent antimicrobial and antioxidant properties confirmed by antimicrobial and DPPH experiments. • In vivo cytotoxicity and brine shrimp lethality assay of synthesized Ag NPs results were discussed. [ABSTRACT FROM AUTHOR]

The high-level of glucose in daily nutrition causes diabetes (Diabetes mellitus) and obesity. It is also important to determine glucose levels in food production processes for quality control methods. Biosensors are bio analytical devices that provides cheap, simple, analyses and have a fast response time. Silver nanoparticles are used to modify electrodes in bio-sensing glucose. The nanoparticles could be synthesized via the green synthesis technique. In this technique, plants could be used both reducing and stabilizing agents. Agricultural waste, an environmental problem, is increasing with the population. These wastes are a good natural source and have the potential for green synthesis of silver nanoparticles to use in biosensor applications. In this study, a new amperometric glucose biosensor was designed. For this purpose, carbon paste electrode (CPE) was modified by green synthesized waste tea based silver nanoparticles (WT-AgNPs) and the glucose oxidase enzyme was immobilized on MCPE by the cross-linking. Glucose determination was performed based on the reduction of hydrogen peroxide at +0.4 V versus Ag/AgCl. The linear working range was determined as 0.10–1.0 µM. In addition, the designed biosensor was applied to detect the amount of glucose in a commercial fruit juice. The results showed that the designed biosensor has low detection limit, very good reproducibility, selectivity, and almost long shelf life. • Food glucose levels must be determined cheaply and rapidly. • Biosensors provides cheap, simple, analyses and have a fast response time. • Agricultural wastes with their bio compounds could be used in silver nanoparticle synthesize. • In this study, waste black tea leaves based silver nanoparticles were synthesized. • The nanoparticles were used to prepare a new amperometric glucose biosensor. [ABSTRACT FROM AUTHOR]

In this work, harvested mushroom substrate (HMS) has been explored for the first time through a comprehensive optimization study for the green synthesis of silver nanoparticles (AgNPs). A multiple response central composite design with three parameters: pH of the reaction mixture, temperature, and incubation period at three distinct levels was employed in the optimization study. The particle size of AgNPs, UV absorbance, and the percentage of Ag/Cl elemental ratio were considered as the response parameters. For each response variable examined the model used was found to be significant (P < 0.05). The ideal conditions were: pH 8.9, a temperature of 59.4 °C, and an incubation period of 48.5 h. The UV–visible spectra of AgNPs indicated that the absorption maxima for AgNP–3 were 414 nm, 420 for AgNPs–2, and 457 for AgNPs-1. The XRD analysis of AgNPs-3 and AgNPs-2 show a large diffraction peak at ∼38.2°, ∼44.2°, ∼64.4°, and ∼77.4°, respectively, which relate to the planes of polycrystalline face-centered cubic (fcc) silver. Additionally, the XRD result of AgNPs–1, reveals diffraction characteristics of AgCl planes (111, 200, 220, 311, 222, and 400). The TEM investigations indicated that the smallest particles were synthesized at pH 9 with average diameters of 35 ± 6 nm (AgNPs–3). The zeta potentials of the AgNPs are −36 (AgNPs–3), −28 (AgNPs–2), and −19 (AgNPs–1) mV, respectively. The distinct IR peak at 3400, 1634, and 1383 cm−1 indicated the typical vibration of phenols, proteins, and alkaloids, respectively. The AgNPs were further evaluated against gram (+) strain Bacillus subtilis (MTCC 736) and gram (−) strain Escherichia coli (MTCC 68). All of the NPs tested positive for antibacterial activity against both bacterial strains. The study makes a sustainable alternative to disposing of HMS to achieve the Sustainable Development Goals (SDGs). [Display omitted] • Harvested Mushroom Substrate utilized for the synthesis of silver nanoparticles. • The synthesis process was further optimized with central composite design. • PH > 9 yielded better morphology of synthesized silver nanoparticles. • The average size of the silver nanoparticles at pH > 9 was 35 ± 6 nm. • Highest bactericidal activity of silver nanoparticles were observed in 6.96 ± 0.03 ppm. [ABSTRACT FROM AUTHOR]

Abstract In this work we report an eco-friendly and low cost method for reducing and capping silver nanoparticles with a lyophilized extract from grape and orange wastes. The synthesis of silver nanoparticles (AgNPs) was monitored by UV–Vis spectroscopy and their characterization was carried out using Transmission Electron Microscopy (TEM), Diffuse Reflectance Infrared Spectroscopy (DRIFT) and X Ray Diffraction (XRD). The AgNPs were crystalline and spherical, with diameters from 3 to 14 nm and 5–50 nm for the nanoparticles obtained from the grape and orange extract, respectively. DRIFT spectroscopy suggested the involvement of various functional groups from extract secondary metabolites during nanoparticle synthesis and capping nanoparticles. The antimicrobial activity of AgNPs was tested against Escherichia coli O157:H7 and Listeria monocytogenes using the agar diffusion method and optical density (OD 600). Non-significant difference of L. monocytogenes growth inhibition was observed between AgNPs obtained from both extracts, demonstrating a 13.5 mm diameter growth inhibition at 100 μg/ml. For E. coli O157:H7, only the AgNPs obtained from the grape extract exhibited a dose-dependent antimicrobial activity showing a final OD of 0.42 at 100 μL. Highlights • Spherical AgNPs of 10–50 nm were prepared using extracts of orange and grape waste. • Phenolic compounds act as reductor and capping agents for AgNPs synthesis. • AgNPs showed antimicrobial activity against E.coli O157:H7 and L. monocytogenes. • Antimicrobial activity is size particle and concentration dependent. [ABSTRACT FROM AUTHOR]

Abstract Green synthesis of silver nanoparticles (AgNPs) is environmentally satisfactory because of their low cost and safe to nature. In the present study, extract of an agricultural waste, coconut (Cocos nucifera) shell is used to synthesize AgNPs and their antibacterial effect was investigated against selected human pathogens Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, Salmonella typhimurium. The AgNPs synthesized using coconut shell extract (CSE-AgNPs) were characterized using UV–Visible spectroscopy (absorption peak at 432 nm), Transmission Electron Microscopy (spherical shaped particles size of 14.2–22.96 nm), Fourier-Transform Infrared Spectroscopy indicating the CSE capping around the AgNPs (Peaks 1384, 1609 and 3418 corresponds to organic molecules) and X-Ray Diffraction (Peak at 32.078 and 2-Theta). CSE-AgNPs exhibited zone of inhibition against S. aureus (15 mm), E. coli (13 mm), S. typhimurium (13 mm) and L. monocytogenes (10 mm) and minimum inhibitory concentration (MIC) of 26, 53, 106 and 212 μg/ml, respectively. Growth curve assay showed the effectiveness of CSE-AgNPs to inhibit the selected pathogens when compared to amphicillin control and extract. Scanning electron microscopy results indicated that the cell wall degradation might be the possible mechanism of antibacterial action of CSE-AgNPs. Different concentrations of AgNPs (0.078–2.5 mg/ml) showed no toxicity against human PBMC cell line. Hence, such highly effective CSE-AgNPs could be explored as antibacterial agent. Highlights • First time we have reported the use of agricultural waste (coconut shell) for the green synthesis of silver nanoparticles. • Nanocharacteristics of AgNPs were confirmed by using UV-VIS spectroscopy, TEM, FTIR and XRD. • Antibacterial activity and cell wall degradation mechanism of CSE-AgNPs were shown against selected human pathogens. [ABSTRACT FROM AUTHOR]

Abstract The present study is focused on the synthesis of silver nano particles (Ag NPs) using an aqueous extract of the whole plant of Sida cordifolia as a potential bio-reducing agent and assessment of their antibacterial activity. UV–Vis spectroscopy of composed silver colloidal solution displayed surface Plasmon resonance peak at 420 nm. XRD and TEM analysis revealed the morphology as ultra-small, monodispersed spherical nanoparticles with face-centered cubic structure and mean particle size of 3–6 nm. This ultra-small nano size might owe to the slow reaction time and phytochemicals existing in the S. cordifolia extract. The Ag NPs are trailed for antibacterial activity against 5 fish (Aeromonas hydrophila , Pseudomonas fluorescence , Flavobacterium branchiophilum, Edwardsiella tarda and Yersinia rukeri) and 4 human (Escherichia coli , Klebsiella pneumonia , Bacillus subtilis and Staphyloccocus aureus) bacterial pathogens. In all the cases, Ag NPs from Sida cordifolia plant extract manifested noteworthy antibacterial effects on par with positive control i.e.; Gentamicin. Highlights • First report on the biosynthesis of Ag NPs using Sida Cordifolia plant extract. • Ultra Small, Monodispersed Ag NPs using green Synthesis. • Act as a good antibacterial agent against various human and fish bacterial pathogens. • Ag NPs were characterized with UV–Vis, XRD, SEM and TEM. [ABSTRACT FROM AUTHOR]

Abstract In the present article, the facile green synthesis of silver nanoparticles (AgNPs) using aqueous leaf extract of Enicostemma axillare (Lam.) has reported. This is a simple, cost-effective, stable for a long time and reproducible aqueous synthesis method to obtain a self-assembly Ag nanoparticles. The size and shape of Ag nanoparticles were characterized by XRD, TEM, and SEM-EDS. The formation and stability of the reduced silver nanoparticles in the colloidal solution were monitored by UV–Vis spectrophotometer analysis. Zeta potential was confirmed by DLS study. The mean particle diameter of silver nanoparticles was calculated from the TEM, SEM and the size of the particles was measured between 15 and 20 nm. TEM analysis revealed the spherical shape of the particles. Crystalline nature of the nanoparticles in the face-centred cubic structure are confirmed by the peaks in the XRD pattern corresponding to (111), (200), (220) and (311) planes. This study showed the biogenic, environmentally friendly and cost-effective synthesis and characterization of the silver nanoparticles. Graphical abstract Graphical abstract for synthesis of AgNPs and their characterization. Image Highlights • Green synthesis of AgNPs is using Enicostemma axillare. • Characterization of AgNPs was done by TEM, SEM and XRD. • The synthesized AgNP solution was stable for more than two months. • The method was eco-friendly, benign and cost-effective. [ABSTRACT FROM AUTHOR]

The green and one-step synthesis of silver nanoparticles (AgNPs) has been proposed as simple and ecofriendly. In the present study, a flower extract of Madhuca longifolia was used for the reduction of silver nitrate into AgNPs, with phytochemicals from the flower extract as a reducing and stabilizing agents. The synthesized AgNPs were spherical and oval shaped and about 30–50 nm sizes. The appearance of a brown color in the reaction mixture is a primary indication of AgNPs formation, and it was confirmed by observing UV-visible spectroscopy peak at 436 nm. The Energy Dispersive X-ray spectra and X-ray diffraction analysis results together confirm that the synthesized nanoparticles contain silver and silver chloride nanoparticles. The Zeta potential analysis indicates presence of negative charges on synthesized AgNPs. The FT-IR study represents involvement of functional groups in AgNPs synthesis. Synthesized AgNPs shows potential antibacterial activity against Gram-positive and Gram-negative pathogens. M. longifolia flower is a good source for AgNPs synthesis and synthesized AgNPs are applicable as antibacterial agent in therapeutics. [ABSTRACT FROM AUTHOR]

Bacteriocins are low molecular weight substances produced through post transcriptional changes. These molecules are easily degraded in mammalian gut by proteolytic enzymes especially protease. Nisin is a peptide with 34 aa and its structure contains a pentacyclic lanthionine and 4 beta metyllanthionine residues. Different formulations have been designed for nisin. Since “green synthesis” is a progressive method to prepare anti-microbial and anti-cancer compounds, this study aimed at green synthesis of nisin metal compounds to be used lower concentration still exerting nisin effects. For this purpose, a 1 mg/ml nisin solution was added to a 1 mM silver nitrate solution and incubated to synthesis nano Ag-nisin, then the optical density of new solution was detected using UV spectroscopy. To determine biomolecules in the Ag-nisin solution, the FTIR method was employed. The size and morphology of Ag-nisin was measured by TEM. The toxicity, inflammatory cytokines production, and intracellular ROS quantity was evaluated using MTT, ELISA and flow-cytometry. XRD pattern indicated the silver crystals in Ag-nisin solution. In addition, FTRI findings showed that the carbonyl groups of amino acid are potently able to bind to metal nanoparticles, cover, and prevent them from particle agglomeration. Treating macrophage cells with 10, 25, 50 and 100 μg/ml of Ag-nisin had no significant effect on the cell viability and intracellular ROS quantity compared to the control group. In addition, different concentrations of Ag-nisin had no effect on the IL-10 and TNF-α levels but caused an increased level of IL-12 in comparison with the control group. In the current study, for the first time, green synthesize was used to prepare Ag-nisin particles. The synthesized nanoparticle is able to induce inflammatory activity via increasing IL-12 without any change in the TNF-α level in macrophage cells. [ABSTRACT FROM AUTHOR]

In the present study, green synthesis of silver nanoparticles (AgNPs) is demonstrated using medicinal herb Swertia paniculata extract. The plant extract acted both as reducing and capping agents during synthesis process, where silver nitrate was used as silver source. Subsequent analysis revealed that particles had size range between 31 and 44 nm and were spherical in shape. Among reaction parameters, temperature and time had significantly influenced the synthesis reaction. Also, synthesized nanoparticles were found stable up to 90 days. Further, antimicrobial activity against gram negative and gram positive bacterial strains was done and results showed that synthesized AgNPs had better antimicrobial activity against Pseudomonas aeruginosa , Klebsiella pneumoniae under standard incubation conditions. Study shows that these particles can be very promising in biomedical applications in future. [ABSTRACT FROM AUTHOR]

In the present study deals with the green synthesis of silver nano particles from methanolic leaf extracts of Atalantia monophylla . The synthesized nano-particles are characterized by UV–vis spectroscopy, PL, FTIR, XRD, SEM with EDAX and TEM. The nano-particles are indicated in absorption peak at 404 nm in the absorption spectrum. Further micro graphical analysis confirmed the average size was estimated about 35 nm and SEAD pattern authorized well crystalline materials. The FTIR studies help to confirm the functional group of synthesized silver nano particles. The XRD data shown the crystalline nature of nano particles and EDAX measurement indicates the purity of silver metal. The antimicrobial effect of silver nanoparticles was tested on pathogenic organisms using agar well diffusion method. Minimum inhibitory concentration (MIC) and Minimum bactericidal/fungicidal concentration (MBC/MFC) were also investigated in different concentrations of leaf extract. The results indicated that synthesized silver nano particle of A. monophylla leaf extract has the potential of antimicrobial activity against pathogenic microorganism. In addition, this is the first report on leaf synthesized silver nano particles of A. monophylla . The antimicrobial activity against pathogenic microorganisms and the ability to detect hydrogen peroxide using the silver nanoparticles were confirmed which would find applications in the development of new antimicrobial drugs and new biosensors to detect the presence of hydrogen peroxide in various samples respectively. [ABSTRACT FROM AUTHOR]

Activated carbon (AC) supported palladium cobalt bimetallic nanoparticles (PdCo@AC NPs) were obtained by green synthesis method using Cinnamomum verum (C. Verum) extract. The obtained NPs were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Crystallography (XRD), Transmission Electron Microscope (TEM) and Ultraviolet Visible (UV-VIS) spectroscopy, and the functional groups and morphology of the nanoparticle were elucidated. The resulting particle size was found to be 2.467 nm. NPs were evaluated using Cyclic Voltammetry (CV), Scan Rate (SR), and Differential Pulse Voltammetry (DPV) techniques for potential dopamine sensors application. According to the obtained DPV results, Limit of Detection (LOD) and Limit of Quantitation (LOQ) values are found to be 5.68 pM and 17.21 pM, respectively. It was also observed that AC supported PdCo nanoparticles obtained from C. verum extract sensed dopamine quite well. Besides, to examine the antibacterial properties of NPs, antibacterial analyzes were performed with Escherichia coli (E. Coli) and Staphylococcus aureus (S. Aureus). It was observed that it showed good antibacterial properties against gram positive (S. aureus) and gram negative (E. coli) bacteria. The study gave important results in terms of the synthesis of bimetallic NPs using the green synthesis method and their usability in different areas. With this study, it was observed that a good antibacterial dopamine sensor were obtained with the successful biogenic synthesis of AC supported PdCo bimetallic NPs. [ABSTRACT FROM AUTHOR]

This study aimed to synthesize Ag NPs as a green catalyst for photocatalytic activity and to examine their biological activities. It was determined that they have high activity in catalytic and biological activities. The green synthesis which is an environmentally friendly and inexpensive method was used to synthesize Ag-NPs using Linum usitatissimum as a reducing agent. Transmission electron microscopy (TEM), infrared to Fourier transform infrared (FTIR) spectroscopy, UV-Visible (UV–Vis) spectroscopy, and X-ray diffraction (XRD) were used to characterize the Ag NPs. In UV–Vis examination, Ag-NPs had intense peaks in the 435 nm region. The antibacterial activity of Ag NPs was investigated, and Ag NPs showed a high lethal effect against S. aureus, E. coli, B. subtilis, and MRSA. In addition, Ag NPs were tested for anticancer activity against the HT-29 colon cancer cell line, MDA-MB-231 breast cancer cell line, healthy cell line L929-Murine Fibroblast cell Lines, and MIA PaCa-2 human pancreatic cancer cell line at various concentrations (1–160 μg/mL) and showed a high anticancerogenic properties against MDA-MB-231 cells. Ag NPs showed the ability of DNA cleavage activity. Also, the antioxidant activity of Ag NPs against DPPH was found to be 80% approximately. Furthermore, the photocatalytic activity of Ag NPs against methylene blue (MB) was determined to be 67.13% at the 180th min. In addition, it was observed that biogenic Ag NPs have high electrocatalytic activity for hydrogen peroxide (H 2 O 2) detection. In the sensor based on Ag NPs, linearity from 1 μM to 5 μM was observed with a detection limit (LOD) of 1.323 μM for H 2 O 2. According to these results, we conclude that the biogenic Ag NPs synthesized using Linum usitatissimum extract can be developed as an efficient biological agent as an antibacterial and anticancer also can be used as a photocatalyst for industrial wastewater treatment to prevent wastewater pollution. [ABSTRACT FROM AUTHOR]

Biodegradable polymeric hydrogels are a unique class of macromolecular networks that can hold a large fraction of an aqueous solvent within their structures. They are particularly suitable for biomedical applications including controlled drug delivery, because of their ability to stimulate biological tissues. Many hydrogel-based networks have been designed and fabricated to meet the needs of pharmaceutical and medical fields. The investigation deals with the environment friendly synthesis of biodegradable semi interpenetrating hydrogel networks based on cross-linked poly(acrylamide) through an optimized rapid redox solution polymerization with N, N′Methylenebisacrylamide (MBA) in presence of Carboxymethylcellulose (CMC).The silver nanoparticles within hydrogel networks as nano reactors have been prepared by green synthesis via insitu reduction of silver nitrate (AgNO 3 ) using Azadirachta Indica (Neem) plant extract under atmospheric conditions. The synthesized nanocomposites were characterised by FTIR spectroscopy, UV–Visible Spectroscopy, Scanning Electron Microscopy (SEM), Transmission electron microscopy (TEM) and Dynamic light scattering (DLS) technique. The thermal properties of the nanocomposite was analyzed by Thermogravimetric Analysis (TGA). The pH response and drug release profile of the synthesised biodegradable Silver-Hydrogel nanocomposite was investigated. Further, it was observed that physicochemical interaction between the polymeric nanocomposites and drug influences the degree of matrix swelling and therefore, its porosity and diffusion release process. [ABSTRACT FROM AUTHOR]

In order to be used in food packaging, the study aims to develop a composite film based on microcrystalline cellulose (MCC) and coated with silver nanoparticles (AgNPs). The MCC was derived from sugar cane bagasse. Protein, starch, and poly-ethylene glycol 1500 (PEG-1500) are employed to improve the tensile strength, flexibility, and durability of the packaging film. The AgNPs was synthesized by a green route employing Azadirachtaindica leaf extract as reducing agent. The determined average crystallite size of AgNPs was seen at 20 nm. The X-ray diffraction (XRD) studies of the final film prepared have an elevated peak with a crystallinity of 37.5%. The scanning electron microscopic images (SEM) of the AgNPs and the prepared samples, reveal their surface morphology. The Fourier transform infrared spectroscopic studies (FT-IR) disclose the functional group changes during the film preparation. The antibacterial activity of the amalgamated AgNPs against five bacterial pathogens studied was found to be highly active against tested food pathogens, except for Proteus vulgari. When coated over a vegetable, the produced nanocomposite film displayed an increased shelf life for the vegetable by limiting the decay impact caused by food pathogens. According to the findings, the AgNPs-impregnated MCC/Starch/Whey protein has the potential to be employed as an antimicrobial packaging material. [Display omitted] • Micro crystalline cellulose (MCC) based composite film impregnated with silver nanoparticles (agnps) has been synthesized. • Synthesized micro crystalline cellulose (MCC) utilized for food packaging applications. • AgNPs-impregnated MCC/Starch/Whey protein has employed as antimicrobial packaging material. [ABSTRACT FROM AUTHOR]

In this work, silver nanoparticles (AgNPs) were synthesized solely using catechin (Ct), a natural polyphenol, then their effects on the growth and metabolism of Aspergillus niger GM13 were investigated using 7.5 and 15 ppm of nanoparticles. AgNPs-Ct, induced physio-metabolic changes activating different stress compensation mechanisms that affect the fungal growth and survival. In particular, 15 ppm of AgNPs-Ct leads to a reduction of 81% of the mycelia biomass. The stress responses in the presence of AgNPs-Ct were further determined by overall cell changes through the production of reactive oxygen species (ROS) by the fungal hyphae. The increase in ROS production confirmed cellular oxidative stress which, together with membrane damage, can be considered to be the main antifungal effect. Adaptative fungal responses during AgNPs-Ct treatment were linked to a high accumulation of trehalose, glycerol, citric and oxalic acid, and several important enzymes involved in the catabolism of nutrients for cell growth, such as acid phosphatase, Naphthol-ASBI phosphohydrolase. The exposure to AgNPs-Ct also triggers changes in the production of VOC derivating from the α- or β-oxidation of fatty acids as alcohols, aldehydes, alkanes, and acids. Herein, the antifungal effect of AgNPs-Ct is demonstrated, elucidating the impact on its physio-metabolic profile. • Surfactant-free AgNPs were synthesized in water exclusively using catechin (Ct). • AgNPs-Ct physio-metabolic effects on A. niger growth were monitored. • AgNPs-Ct induces a redox homeostasis imbalance and osmotic disequilibrium. • Adaptation and defense mechanisms of A. niger were evidenced. • AgNPs-Ct are sustainable emerging biocontrol agents with promising features. [ABSTRACT FROM AUTHOR]

Green synthesis of silver nanomaterial plays a pivotal role in the growing field of nanotechnology. Development of anti-parasitic drugs from plant metabolites has been in regular practice from the ancient period but most of them were discarded due to their inefficiency to control diseases effectively. At present, nanoparticles are used for developing anti-parasitic therapy for their unique properties such as smallest in size, bio-ability, bio-compatibility and penetration capacity into a cell. The present study aims at synthesis of silver nanoparticles (AgNPs) by using funicles extract of Acacia auriculiformis and tests its efficacy as antifilarial. Experimental evidence show that AgNPs are effective at a very low concentration compared to crude plant extracts. Synthesis of these nanoparticles is a single-step, biogenic, cost effective and eco-friendly process. Synthesized nanoparticles were characterized by UV–Vis spectroscopy, TEM, SAED, FTIR, EDX, FESEM and Z-potential. The antifilarial efficacy of AgNPs was tested against different life cycle stages of bovine filarial parasite Setaria cervi by morphological study, motility assessment and viability assay. These nanoparticles are found to have antifilarial activity with LC 50 of 5.61 μg/mL and LC 90 of 15.54 μg/mL against microfilaria of S. cervi . The microscopic findings and the detailed molecular studies confirmed that green synthesized AgNPs were effective enough to induce apoptosis through up regulation of ROS (reactive oxygen species). [ABSTRACT FROM AUTHOR]

Hypothesis Biological synthesis of silver nanoparticles is a cost effective natural process where the phytochemicals specifically phenols, flavonoids and terpenoids present in the plant extracts act as capping and reducing agent. Due to their nano size regime the silver nanoparticles may directly bind to the DNA of the pathogenic bacterial strains leading to higher antimicrobial activity. Experiment In the current study silver nanoparticles were synthesised using plant extracts from different origin Cucurbita maxima (petals), Moringa oleifera (leaves) and Acorus calamus (rhizome). The synthesised nanoparticles were characterized by UV–visible spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD), field emission scanning electron microscopy (Fe-SEM) and Fourier transform infrared spectroscopy (FTIR). Finding Highly crystalline, roughly spherical and cuboidal silver nanoparticles of 30–70 nm in size were synthesised. The nanoparticles provided strong antimicrobial activity against pathogenic strains. The effect of the synthesised nanoparticles against A431 skin cancer cell line was tested for their toxicity by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) dye. The IC 50 values of 82.39 ± 3.1, 83.57 ± 3.9 and 78.58 ± 2.7 μg/ml were calculated for silver nanoparticles synthesised by C. maxima , M. oleifera and A. calamus respectively. [ABSTRACT FROM AUTHOR]

In this work, silver nanoparticles have been synthesized by wet chemical technique, green synthesis and microbial methods. Silver nitrate (10 −3 M) was used with aqueous extract to produce silver nanoparticles. From the results it was observed that the yield of nanoparticles was high in green synthesis. The size of the silver nanoparticles was determined from Scanning Electron Microscope analysis (SEM). Fourier Transform Infrared spectroscopy (FTIR) was carried out to determine the presence of biomolecules in them. Its cytotoxic effect was studied in cancerous cell line and normal cell line. MTT assay was done to test its optimal concentration and efficacy which gives valuable information for the use of silver nanoparticles for future cancer therapy. [ABSTRACT FROM AUTHOR]

Increasing demand of pure and accessible water and improper disposal of waste into the existing water resources are the major challenges for sustainable development. Nanoscale technology is an effective approach that is increasingly being applied to water remediation. Compared to conventional water treatment processes, silver nanotechnology has been demonstrated to have advantages due to its anti-microbial and oligodynamic (biocidal) properties. This review is focused on environmentally friendly green syntheses of silver nanoparticles (AgNPs) and their applications for the disinfection and microbial control of wastewater. A bibliometric keyword analysis is conducted to unveil important keywords and topics in the utilisation of AgNPs for water treatment applications. The effectiveness of AgNPs, as both free nanoparticles (NPs) or as supported NPs (nanocomposites), to deal with noxious pollutants like complex dyes, heavy metals as well as emerging pollutants of concern is also discussed. This knowledge dataset will be helpful for researchers to identify and utilise the distinctive features of AgNPs and will hopefully stimulate the development of novel solutions to improve wastewater treatment. This review will also help researchers to prepare effective water management strategies using nano silver-based systems manufactured using green chemistry. [Display omitted] • Evolution in research on AgNPs for water treatment is examined bibliometrically • Bio-based synthesis of AgNPs is simple, robust, eco-friendly and cost-effective. • AgNPs composites can be used to remove emerging pollutants. • Antibacterial mechanism of AgNPs is discussed for disinfection and microbial control. • Future perspectives and their potential applications are proposed. [ABSTRACT FROM AUTHOR]

Scutellaria multicaulis is a medicinal herb which has been extensively prescribed in Iranian traditional medicine for treatment of infections, constipation, wounds, and also as medication for anxiety. To evaluate biological activities of biosynthesized silver nanoparticles (Sm-AgNPs), Sm-AgNPswere synthesized using S. multicaulis stem extract as capping and reducing agent. Characterization studies using UV–vis, XRD, DLS, Zeta potential, FESEM, EDX, TEM, FTIR, RAMAN and TGA assays indicated that Sm-AgNPs had optimal shape, size (∼60 nm) and stability (−46.4 mV) to be used as a drug. Findings also demonstrated that Sm-AgNPs display higher Total Phenolics and Total Flavonoids Content and possesses higher antioxidant activity. HPLC-MSn analysis of constituents in the S. multicaulis stem extract and Sm-AgNPs-free supernatant in negative ion mode showed that flavonoids, mainly jaceidin, skullcapflavon II, wogonin, oroxylin A and dihydroxy, trimethoxyflavone from extract have contributed to the synthesis of Sm-AgNPs. Additionally, Sm-AgNPs demonstrated effective anticarcinogenic properties on MDA-MB231 cells proliferation with IC 50 value of 81.2 μg/mL at 48 h by inducing cell apoptosis. Overall, results confirmed the potential role of S. multicaulis stem extract as a potential raw material for synthesis of biologically active Sm-AgNPs, for development of new antitumor agents which could be utilized to combat breast cancer. [Display omitted] •Biosynthesis of Sm-AgNPs using S. multicaulis stem extract with potential anticancer activity. •Synthesis of flavonoid and phenolic rich content Sm-AgNPs with significant antioxidant activity. •Optimal shape, size and stability of Sm-AgNPs, the main reason for their apoptotic activity. [ABSTRACT FROM AUTHOR]

In this study, a natural extract from the plant Radix hedysari (ER) was proven to be useful for the green synthesis of silver nanoparticles (AgNPs) and ER-AgNPs in particular. Considering the complexity of plant extracts, high-pressure liquid chromatography (HPLC) was effective at confirming the components of ER, surprisingly, formononetin was found to comprise more than 85% of the total contents. Since formononetin was confirmed to be the primary component of ER, this compound was also used as the basis to synthesize AgNPs designated FMT-AgNPs that was highly pure and of high quality. The FMT-AgNPs functionalized by formononetin were optimized for further study. A simple, fast and sensitive colorimetric method detect formothion was achieved using FMT-AgNPs. A wide linear range from 0.1 μM to 10 μM was established with a low limit of detection (LOD) of 14.6 nM. Since formononetin performed multiple roles during the synthesis, it was confirmed that the mechanism of detection was based on aldol condensation, intermolecular hydrogen bonds and electrostatic attraction between formononetin and formothion. Finally, the green synthesized FMT-AgNPs were further applied in typical fruit and vegetable samples, indicating that FMT-AgNPs were potentially highly useful. [Display omitted] • The plant extract (ER) and formononetin was utilized to green synthesize silver nanoparticles (ER-AgNPs/FMT-AgNPs). • FMT-AgNPs were proven to be pure and of high quality. • The relevant synthesis or mechanism of detection was clearly explained. • FMT-AgNPs were sensitive and selective for the detection of formothion. • FMT-AgNPs were applied to detect formothion in typical vegetable and fruit samples. [ABSTRACT FROM AUTHOR]

Plant-mediated synthesis of silver nanoparticles (Ag NPs) is a green and economically viable method, which can offer numerous benefits over traditional chemical and physical methods. In this paper, three fruit extracts (tomato, orange, and grapefruit) served simultaneously as stabilizing and reducing agents during the biosynthesis of Ag NPs. The formation of Ag NPs, were monitored using the UV–visible absorption spectra of Ag NPs which exhibited three distinct bands centered at 439, 413, and 410 nm. SEM and TEM analysis indicated that these bands corresponded to three distinct spherical-shaped Ag NPs having average particle sizes of 73, 24, and 31 nm, respectively. XRD and EDS spectral analyses were used to verify the degree of crystallinity, nanostructure, and presence of Ag NPs. Advanced analysis using XPS, FTIR, and GC-MS indicated that the Ag NPs were coated with a variety of organic compounds including acids, aldehydes, esters, and ketones, indicating that fruit derived phytochemicals had a significant role in synthesis, and subsequently a mechanism of Ag NPs formation was proposed. The fabricated nanoparticles were also successfully used in Fenton-like oxidation for the environmental remediation of estrone and estriol, with removal efficiencies of 52.1 and 35.9%, respectively. • Three different fruit extracts were used to synthesize Ag NPs. • Biomolecules in fruit extracts were confirmed. • Formation of Ag NPs by fruit extracts was proposed. • Green Ag NPs were useful as a catalyst to remove estrogen from aqueous solution. [ABSTRACT FROM AUTHOR]

Despite the development potential in the field of nanotechnology, there is a concern about possible effects of nanoparticles on the environment and human health. In this study, silver nanoparticles (AgNPs) were synthesized by ‘green’ and ‘chemical’ methods. In the wet-chemistry method, sodium borohydrate, sodium citrate and silver nitrate were used as raw materials. Leaf extract of Nigella sativa was used as reducing as well as capping agent to reduce silver nitrate in the green synthesis method. In addition, toxic responses of both synthesized AgNPs were monitored on bone-building stem cells of mice as well as seed germination and seedling growth of six different plants (Lolium, wheat, bean and common vetch, lettuce and canola). In both synthesis methods, the colorless reaction mixtures turned brown and UV–visible spectra confirmed the presence of silver nanoparticles. Scanning electron microscope (SEM) observations revealed the predominance of silver nanosized crystallites and fourier transform infra-red spectroscopy (FTIR) indicated the role of different functional groups in the synthetic process. MTT assay showed cell viability of bone-building stem cells of mice was further in the green AgNPs synthesized using black cumin extract than chemical AgNPs. IC50 (inhibitory concentrations) values for seed germination, root and shoot length for 6 plants in green AgNPs exposures were higher than the chemical AgNPs. These results suggest that cytotoxicity and phytotoxicity of the green synthesized AgNPs were significantly less than wet-chemistry synthesized ones. This study indicated an economical, simple and efficient ecofriendly technique using leaves of N. sativa for synthesis of AgNPs and confirmed that green AgNPs are safer than chemically-synthesized AgNPs. [ABSTRACT FROM AUTHOR]

During this study, we report the green synthesis of silver nanoparticles (Ag NPs) using Euphorbia helioscopia Linn leaf extract for the synthesis of propargylamines. Also, the structural and optical properties are studied. The synthesized nanoparticles are characterized by TEM, XRD, FT-IR and UV–visible techniques. UV–visible studies show an absorption band at 440 nm due to surface plasmon resonance (SPR) of the silver nanoparticles. Furthermore, the catalyst exhibits high catalytic activity, superior cycling stability and excellent substrate applicability. [ABSTRACT FROM AUTHOR]

In this study a synthetic approach for the stable, mono-dispersed high yielding bimetallic (Ag-Se) nanoparticles by quercetin and gallic acid is described. The bimetallic nanoparticles were synthesized at room temperature. Different reaction parameters (concentration of quercetin, gallic acid and Ag/Se salt, pH, temperature and reaction time) were optimized to control the properties of nanoparticles. The nanoparticles were characterized by various analytical techniques and their size was determined to be 30-35 nm. Our findings suggest that both the reduction as well as stabilization of nanoparticles were achieved by the flavonoids and phenolics. This study describes the efficacy of quercetin and gallic acid mediated synthesis of bimetallic (Ag-Se) nanoparticles and their in vitro antioxidant, antimicrobial (Gram-positive and Gram-negative bacteria) and antitumor potentials. The synthesized Ag-Se nanoparticles were used as anticancer agents for Dalton lymphoma (DL) cells and in in vitro 80% of its viability was reduced at 50 μg/mL. [ABSTRACT FROM AUTHOR]

The demand for the green synthesis of nanoparticles has gained prominence over the conventional chemical and physical syntheses, which often entails toxic chemicals, energy consumption and ultimately lead to negative environmental impact. In the green synthesis approach, naturally available bio-compounds found in plants and fungi can be effective and have been proven to be alternative reducing agents. Fungi or mushrooms are particularly interesting due to their high content of bioactive compounds, which can serve as excellent reducing agents in the synthesis of nanoparticles. Apart from the economic and environmental benefits, such as ease of availability, low synthesis/production cost, safe and no toxicity, the nanoparticles synthesized from this green method have unique physical and chemical properties. Stabilisation of the nanoparticles in an aqueous solution is exceedingly high, even after prolonged storage with unperturbed size uniformity. Biological properties were significantly improved with higher biocompatibility, anti-microbial, anti-oxidant and anti-cancer properties. These remarkable properties allow further exploration in their applications both in the medical and agricultural fields. This review aims to explore the mushroom-mediated biosynthesis of nanomaterials, specifically the mechanism and bio-compounds involved in the synthesis and their interactions for the stabilisation of nanoparticles. Various metal and non-metal nanoparticles have been discussed along with their synthesis techniques and parameters, making them ideal for specific industrial, agricultural, and medical applications. Only recent developments have been explored in this review. [Display omitted] • A detailed mechanism contributing to the mycogenic synthesis of NPs has been described. • Demonstrates the role of different mushroom species to different sizes, shapes, stability and homogeneity of NPs. • Provides ideal physical and chemical properties of the mycogenic synthesized NPs. • Illustrates properties as well as unique applications arising from species-specific NPs. • Explores wider applications extending to biomedical, environmental and industrial sectors. [ABSTRACT FROM AUTHOR]

In the present study, a simple, cheaply and environmental friendly method was evaluated for the synthesis of silver nanoparticle via Cupressus sempervirens L. (CSPE) pollen extract as reducing and stabilizing agent. Various parameters such as volume of CSPE, temperature and reaction time on AgNPs formation were investigated spectrophotometrically to optimize reaction conditions. The electrochemical behavior of the biosynthesized AgNPs were investigated by cyclic voltammetry and square wave voltammetry techniques. An electrosensor based on AgNPs modified glassy carbon electrode were constructed and tested on electro reduction of hydrogen peroxide in phosphate buffer medium. The prepared electrosensor could detect the H 2 O 2 in the range of 5.0 μM - 2.5 mM with a detection limit of 0.23 μM. In addition, the antioxidant activity of biosynthesized AgNPs were evaluated against DPPH free radical. Results obtained from the antioxidant study suggested that CSPE mediated AgNPs exhibit a good antioxidant effect. [Display omitted] ● AgNPs were synthesized successfully via Cupressus sempervirens pollen extract. ● A novel hydrogen peroxide sensor based on pollen extract mediated AgNPs were described. ● The AgNPs-GCE electrosensor showed a linear response to hydrogen peroxide concentration from 5.0 μM to 2.5 mM with a detection limit of 0.23 μM. ● Pollen extract mediated AgNPs exhibit a good antioxidant effect. [ABSTRACT FROM AUTHOR]

Silver nanoparticles (AgNPs), as well as silver ions, are described as toxic to a broad spectrum of microorganisms, especially bacteria. In contrast to this, a current trend is to develop and carry out the in vitro cultivation of microorganisms, facilitating the study of interactions between populations of cells and species. Thus, the goal of this study was to evaluate the behavior, growth, and swarming formation of bacteria under conditions of co-culture in solid medium modified with AgNPs. The aqueous extract from the leaves of Handroanthus serratifolius was used to chemically reduce silver nitrate (AgNO 3) solution, forming AgNPs. This synthesis route was performed in an aqueous medium at 50 °C for 3 h. The hydrodynamic diameter (HD) and polydispersity index (PdI) were obtained by dynamic light scattering (DLS), and Zeta potential (ZP) of the AgNPs were measured by electrophoretic mobility. Atomic force microscopy (AFM) was used to evaluate the shape of the AgNPs. Luria Bertani (LB) medium was used for the liquid culture steps and for the solid medium, bacterial agar was added. Solutions containing AgNPs or AgNO 3 were added at final concentrations of 256, 128, or 64 μM. Subsequently, microorganism Escherichia coli ATCC® 8739 and Staphylococcus aureus ATCC® 25923 were plated with AgNPs, AgNO 3 , and control media. Analyses of the AgNPs showed an average HD of 76.02 ± 3.08 nm, PdI of 0.461 ± 0.012, and ZP of −21.5 ± 2.2 mV; in addition, AgNPs were nearly spherical. The solid culture medium elaborated and modified with AgNPs at the concentrations of 256 and 128 μM inhibited the growth of the tested microorganisms and decreased the swarming formation. However, those media modified at a concentration of 64 μM did not induce any alteration in the growth and proliferation of the microorganisms. Furthermore, it was observed that plates containing modified culture media with 128 μM, increased proximity between both co-cultured bacteria occurred. Thus, the application of AgNPs in solid culture media becomes a promising and potentially reproducible strategy for evaluating the behavior, swarming formation, and toxicity of AgNPs, making the understanding of possible bactericidal or bacteriostatic effects, and also colonizing strategies. • Aqueous extract of Handroanthus serratifolius form AgNPs by green synthesis. • Modified solid culture medium supplemented with AgNPs in different concentrations. • Low concentrations of AgNPs do not interfere with the growth of microorganisms. • High concentrations of AgNPs inhibit the growth and development of microorganisms. • Incorporation of a AgNPs to culture medium modulates the co-cultivation of bacteria. [ABSTRACT FROM AUTHOR]

A sustainable approach for the green synthesis of silver nanoparticles (AgNPs) using an aqueous extract of hyperpigmented tomato (Solanum lycopersicum L) skins (HTS) was described. AgNPs characterization and catalytic activity in the degradation of methylene blue were reported. The influence of some experimental parameters on synthesis, such as green extract concentration, pH, microwave irradiation time, as well as stabilization time, was investigated. HTS extract was initially characterized regarding its reducing potential, Fourier Transform Infrared (FTIR) molecular fingerprinting and 1H NMR metabolite profiling and then used as a reducing-stabilizing agent for the green synthesis of AgNPs. Furthermore, a comparative study, with chemically synthetized AgNPs, was carried out and the catalytic activity of synthesized nanoparticles in the reduction of methylene blue was studied by UV–visible spectrophotometer. Obtained AgNPs were analyzed by ultraviolet–visible spectroscopy, FTIR, scanning electron microscopy and electrochemical analyses (cyclic and anodic stripping voltammetry). In general, obtained AgNPs were spherical in shape, with a diameter ranging from 21 to 93 nm, and very stable over time. Interestingly, a red shift of the surface plasmon resonance of green nanoparticles was observed as the volume of the HTS extract increased. Lastly, an improved catalytic activity in the reduction of methylene blue was detected in the case of green synthesized nanoparticles, with respect to those conventionally produced. • Hyperpigmented tomato skins were used for silver nanoparticles production. • Hyperpigmented tomato skin extracts were analyzed by spectroscopic and chromatographic analyses. • Reducing sugars are the major reducing components in the extracts. • Obtained silver nanoparticles were fully characterized. • Green nanoparticles showed better catalytic properties than chemically synthetized counterparts. [ABSTRACT FROM AUTHOR]

A green synthesis method for nanoscale silver using β-cyclodextrin as both reducing agent and stabilizer was developed. β-cyclodextrin was used not only as a reducing agent but also a stabilizing agent for nano-silver, and is also an excellent detection substrate due to its special structure (inner hydrophobic and outer hydrophilic ring structure). Then, the green synthesized silver nanoparticles were used as Surface-enhanced Raman spectroscopy (SERS) enhanced substrates to detect polycyclic aromatic hydrocarbons, such as: anthracene, pyrene, chrysene and triphenylene. The SERS substrate can be used for both quantitative detection of the four polycyclic aromatic hydrocarbons and qualitative identification of mixtures of these hydrocarbons. This synthesis method is simple and convenient, having great potential in simultaneous and rapid detection of environmental organic pollutants. Image 1 • A green synthesis method of nano silver surface reinforced substrate is introduced in this paper. • β-cyclodextrin could be used both as a reducing agent and as a stabilizer because of its unique structure. • The enhanced substrate synthesized by this method can be used for the detection of polycyclic aromatic hydrocarbons. [ABSTRACT FROM AUTHOR]

• Cost-effective synthesis of silver nanoparticles using Crataegus pentagyna fruit extract is reports for the first time. • The CP -AgNPs was characterized using XRD, FT-IR, EDS, TEM, SEM, DLS and UV–Vis. • Spherical CP -AgNPs showed a high photocatalytic and antibacterial activities in the degradation of organic pollutants and various bacteria, respectively. • As-synthesized silver nanoparticles were used against multi-drug resistance gram negative and gram positive of bacteria. In this work, a cost-effective/green/high-efficient/facile process for the preparation of silver nanoparticles using C. pentagyna (CP -AgNPs) fruit extractas as reducing agent and capping agent was reported. The influence of different parameters including temperature, pH, concentration and time were studied to reach optimum conditions. The as-synthesized CP -AgNPs were characterized using UV/Vis, XRD, SEM, TEM, EDS and DLS analysis. Regular, spherical morphology and homogeneous of CP -AgNPs with a mean particles size of 25–45 nm was determined from TEM images. The CP -AgNPs in presence of sunlight catalyzed the degradation of the organic contaminant dyes, rhodmine b (RhB), eosin (EY) and methylene blue (MB) with percent degradation of 85% and 70% and 78%, respectively. In addition, CP -AgNPs exhibit antibacterial activities against seven ATCC strains of bacteria and eight strains of drug-resistant bacteria. Due to the results, CP -AgNPs enhanced antimicrobial potential against S. aureus, E. faecalis , P. aeruginosa , A. baumannii and E. coli with MIC and MBC of (0.11, 7.1 µg/ml), (0.11, 1.7 µg/ml), (0.11, 0.22 µg/ml), (0.11, 0.22) and (0.11, 0.44 µg/ml), respectively. Generally, CP-AgNPs have excellent potential application for the photocatalytic degradation of organic pollutant and in the development of antibacterial materials. [ABSTRACT FROM AUTHOR]