Green synthesis of copper oxide nanoparticles using Abutilon indicum leaf extract: Antimicrobial, antioxidant and photocatalytic dye degradation activities

Purpose: To synthesize copper oxide (CuO) nanoparticles using a ecofriendly technique and evaluate their antimicrobial, antioxidant and photo-catalytic dye degradation potentials. Methods: A superficial method (solution combustion method) was employed for the synthesis of copper oxide nanoparticles from an aqueous extract of Abutilon indicum. The CuO nanoparticles were characterized using x-ray diffraction (XRD), energy-dispersive x-ray spectroscopy (EDX), scanning electron microscope (SEM) and ultraviolet-visible (UV-Vis) spectroscopic techniques. The antimicrobial activity of the CuO nanoparticles was determined by agar well diffusion method, while their antioxidant properties were assessed by DPPH radical scavenging, ferric reducing antioxidant power (FRAP), total antioxidant, ferric thiocyanate (FTC) and total phenolic content (TPC) assays. The photo-catalytic degradation activity of synthesized CuO nanoparticles was assessed by the degradation of Acid Black 210 (AB) dye under sunlight irradiation. Results: XRD, EDX and SEM results confirmed successful synthesis of CuO nanoparticles, with hexagonal, wurtzite and sponge crystal structure. Photo-catalytic data revealed that the nanoparticles are a good catalyst for effective degradation of Acid Black 210. The nanoparticles also exhibited remarkable antioxidant activity, with IC50 and FRAP values ranging from 40 +/- 0.23 to 84 +/- 0.32 mu g/ml, and 0.65 +/- 0.01 to 9.10 +/- 0.21 Trolox equivalent/mL, respectively. Significant bactericidal activity was manifested by the CuO nanoparticles against Klebsiella and Bacillus subtilis with zone of inhibition of 14 +/- 0.05 and 15 +/- 0.11 mm, respectively. Conclusion: The synthesized CuO nanoparticles exhibit antibacterial and antioxidant potential, indicating that they are good candidates for future therapeutic applications.