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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]

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]

• 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]