Green synthesis of copper oxide nanoparticles using Arachis hypogaea shell extract and evaluation of its antioxidative, antidiabetic and antibacterial properties

This investigation aimed to employ a green synthesis procedure to fabricate copper oxide nanoparticles (CuO-NPs) from peanut shell extract ( Arachis hypogaea ). Characterization of the synthesized CuO-NPs was conducted utilizing UV‒Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy dispersive X-ray (EDX), and field emission scanning electron microscopy (FE‒SEM). The synthesized particles showed a color change pattern during synthesis and it showed a broad peak at 292 ɳm and analyzed using UV–Vis spectroscopy. The morphology of the sample was found to be spherical aggregated from the SEM and XRD, with an average grain size of 25.23 ɳm and 19.30 ɳm crystallite size, respectively. The FTIR data validated the presence of bioactive functional groups which are crucial in capping and stabilizing the CuO-NPs. At a concentration of 500 µg/mL, the produced CuO-NPs demonstrated strong antioxidant activity (scavenging activity was 66.47 ± 1.58%) in the DPPH experiment. An α-amylase inhibition assay was carried out using DNSA method, which showed anti-diabetic activity with maximum inhibition of 63.23 ± 1.36% at 100 µg/mL for CuO-NPs. The antibacterial evaluation showed that CuO-NPs was the most effective with zone of inhibition (mm) Escherichia coli (10.0 ± 0.50), Salmonella typhi (11.0 ± 0.15), Bacillus subtilis (18.5 ± 0.25), and Staphylococcus aureus (14.0 ± 0.50), at minimum inhibitory concentration of 0.2 g/mL Hence, the CuO-NPs prepared using peanut waste extract (PWE) can be used as potential candidates for biomedical applications.