Different Fruit Extracts Mediated Synthesis of Spherical Copper Nanoparticles for Methylene Blue Dye Degradation, Antimicrobial, and Antioxidant Properties

This work presents an eco‐friendly synthesis of copper nanoparticles (CuNPs) utilizing aqueous extracts of four fruits: Emblica officinalis (amla, EG), Tamarindus indica (TI), Citrus sinensis (sweet orange, CS), and Actinidia deliciosa (kiwifruit, AD). The synthesized CuNPs were characterized using UV–visible spectroscopy, X‐ray diffraction (XRD), Fourier‐transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy‐dispersive X‐ray spectroscopy (EDX). UV–vis spectra of all four fruit extracts based on CuNPs exhibited a surface plasmon resonance band around 580 nm, confirming Cu nanoparticle formation. XRD patterns indicated a face‐centered cubic (FCC) crystalline structure, with TEM images revealing spherical nanoparticles averaging ∼20 nm in diameter. FTIR analysis suggested the involvement of phytochemicals in the reduction and stabilization of CuNPs. The photocatalytic activity of the CuNPs was evaluated through the degradation of methylene blue (MB) dye under sunlight, achieving up to 76% degradation within 60 min. Antibacterial assays demonstrated significant inhibition zones against both Gram‐positive ( Bacillus subtilis, Staphylococcus aureus ) and Gram‐negative ( Escherichia coli, Pseudomonas aeruginosa ) bacteria. Additionally, the CuNPs exhibited notable antioxidant activity, as determined by the reducing power assay method. These findings highlight the potential of fruit‐extract‐mediated CuNPs in environmental remediation and biomedical applications.