Facile and green synthesis of copper oxide nanoparticles using Pithecellobium dulce seed pods and their antioxidant, anticancer, and catalytic applications

Abstract

The present investigation focussed on the biogenic synthesis of copper oxide nanoparticles (CuO NPs) from Pithecellobium dulce seed pods, which were used as reducing and stabilizing agents. Various analytical techniques were used to characterize the synthesized CuO nanoparticles (CuO NPs), including UV–visible, Scanning Electron Microscopy (SEM), Energy-dispersive X-ray (EDAX) spectroscopy, Fourier Transform Infrared (FTIR), Transmission Electron Microscopy (TEM) and X-ray diffraction (XRD) analysis. XRD analysis revealed that the synthesized CuO NPs were crystallized in a single phase. FTIR spectroscopy revealed that the functional groups of phytochemicals facilitated the conversion of Cu²⁺ ions into CuO NPs and concurrently stabilized these nanoparticles. TEM analysis revealed that CuO NPs are spherical and have an average size of 13 ± 3 nm. CuO NPs exhibited significant antioxidant and anticancer activity. CuO NPs were also tested for their catalytic ability to reduce methylene blue dye in the presence of NaBH₄. The 90.75% DPPH scavenging activity for CuO NPs was observed at the highest concentration (110 µL). The degradation efficiency for methylene blue (MB) was found to be 98.7%. The PFO (pseudo-first order) model was utilized to describe the kinetics of the reduction process, and the reaction rate constant (k) was 0.337 min⁻¹. It was found that CuO NPs reduced methylene blue dye with significant catalytic efficiency. Biomedical applications, as well as water remediation, can be achieved through the use of CuO NPs.