Biogenic fabrication of CuNPs, Cu bioconjugates and assessment of antimicrobial and antioxidant activity.

In the present study, the authors synthesised copper nanoparticles (CuNPs) by using extract of (ginger) and later the NPs were bioconjugated with nisin, which shows antimicrobial activity against food spoilage microorganisms. CuNPs and its bioconjugate were characterised by ultraviolet-vis spectroscopy, NP tracking analysis, Zetasizer, transmission electron microscopy analysis, X-ray diffraction and Fourier transform infra-red (FTIR) spectroscopy. Zeta potential of CuNPs and its bioconjugate were found to be very stable. They evaluated efficacy of CuNPs and its bioconjugate against selected food spoilage bacteria: namely, , and fungi including and Antimicrobial activity of CuNPs was found to be maximum against (18 mm) and the least activity was noted against (13 mm). Antioxidant activity of CuNPs and ginger extract was performed by various methods such as total antioxidant capacity reducing power assay, 1-1-diphenyl-2-picryl-hydrazyl free radical scavenging assay and hydrogen peroxide assay. Antioxidant activity of CuNPs was higher as compared with ginger extract. Hence, CuNPs and its bioconjugate can be used against food spoilage microorganisms.