Comparative biomedical and photocatalytic efficacy of Malvastrum coromandelianum (L.) aqueous extract-assisted green synthesized zinc oxide and copper oxide nanoparticles.

Abstract

This study presents the biogenic synthesis of CuO nanoparticles (NPs) and ZnO NPs using aqueous leaf extract of Malvastrum coromandelianum as a green reducing and stabilizing agent. The synthesized NPs were characterized by UV-vis, PXRD, FTIR, ZP, DLS, SEM, TEM, BET, and EDX. The photocatalytic potential of the synthesized NPs was evaluated by degrading methylene blue (MB) and methyl orange (MO) dyes under sunlight. The synthesized ZnO and CuO NPs also exhibited remarkable biomedical applications by showing strain-specific antibacterial activity and substantial antioxidant properties assessed by DPPH, FRAP, and TPC assays. CuO NPs were more effective against L. monocytogenes and S. enterica, with minimum inhibitory concentration (MIC) values of 15 ± 0.85 and 13 ± 1.75 mg/mL, respectively, while ZnO NPs targeted P. aeruginosa more efficiently, with an MIC value of 12 ± 1.9 mg/mL. CuO NPs have also demonstrated better antioxidant efficacy than ZnO NPs, assessed by DPPH, FRAP, and TPC assays. All these applications highlighted the photocatalytic and biomedical efficacy of green-synthesized CuO NPs and ZnO NPs.