Multifunctional copper oxide nanoparticles from Solanum nigrum: Photocatalysis, antimicrobial activity, and phytotoxicity evaluation

Abstract

Green synthesis of nanoparticles using plant extracts offers an eco-friendly, cost-effective, and energy-efficient alternative to conventional methods. In this study, Copper Oxide nanoparticles were biosynthesized using Solanum nigrum leaf extract, and phytochemical screening identified bioactive compounds responsible for reduction and stabilization. The nanoparticles were characterized by UV–Vis spectroscopy, showing a characteristic absorbance peak at 243 nm, Fourier Transform Infrared Spectroscopy (FTIR) to identify surface functional groups, X-Ray Diffraction (XRD) with an average crystallite size of 43.69 nm, and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM–EDS) to analyze morphology and elemental composition. Their photocatalytic activity was evaluated by degrading Metanil Yellow dye, showing 79.44 % decolorization efficiency. Antibacterial activity was assessed via the agar well diffusion method, with Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) determined against pathogenic strains. Phytotoxicity assessment using Macrotyloma uniflorum (horse gram) indicated biocompatibility and environmental safety. These findings indicate that Solanum nigrum-mediated Copper oxide nanoparticles possess effective photocatalytic and antibacterial properties with low phytotoxicity, highlighting their potential for wastewater treatment and antimicrobial applications.