Harnessing Hemidesmus indicus for eco-friendly CuO nanoparticle synthesis and evaluating its antioxidant and mosquito larvicidal activities

Abstract

CuO NPs were successfully synthesized using H. indicus leaves extract and evaluated for their antioxidant and mosquito larvicidal activities. The structural, compositional, and morphological properties of the synthesized NPs were thoroughly characterized by UV–visible spectroscopy confirmed successful synthesis with absorption wavelength of 229 nm in the aqueous suspension. The FTIR Cu–O stretching in CuO NPs is confirmed by bands at 447 cm ⁻¹, 478 cm ⁻¹, and 517 cm⁻¹, while polyphenols and flavonoids interact with Cu⁺² ions, as indicated by peaks at 3340 cm⁻¹ (O–H), 1599 cm⁻¹ (C=O/aromatic C=C), and 1070 cm⁻¹ (C–O), with phenols playing a role in stabilization. SEM analysis revealed a distinctive flower-like morphology of the CuO NPs with an average particle size of 64.17 nm. The EDX analysis confirmed the elemental composition, with the average weight percentage (Wt. %) of copper at 12.55% and atomic percentage (At. %) at 20.92%. The PXRD analysis, compared with ICDD card No. 01-080-1916, reveals a monoclinic crystalline structure with 90.8% crystallinity and an average particle size of 8.27 nm. The antioxidant activity of the CuO NPs was evaluated using the DPPH assay, yielding an IC₅₀ value of 1.042 mg/mL, indicating notable free radical scavenging potential. In mosquito larvicidal tests, the nanoparticles exhibited a dose-dependent increase in mortality rates. These findings highlight the simplicity, cost-effectiveness, and eco-friendly nature of the synthesis method. The synthesized CuO NPs, with demonstrated antioxidant and larvicidal activities, hold significant promise for biomedical and environmental applications.