Green Synthesis of Copper Oxide Nanoparticles from Hybiscus rosa-sinensis Extracts with Enhanced Bioactivity

Abstract

Nanotechnology offers new opportunities in biomedical and environmental research, with copper oxide nanoparticles (CuONP) becoming popular due to their unique physical and chemical properties and diverse biological applications. In this study, CuONP were synthesised using Hibiscus rosa-sinensis leaf extract through a green synthesis method, with phytochemicals serving as natural stabilisers. A colour change indicated the formation of CuONP, which was then characterised using UV-Vis spectroscopy, FTIR, XRD, and SEM analyses. The UV-Vis spectra showed a strong absorption peak at 260-280 nm, confirming successful nanoparticle formation. FTIR identified hydroxyl, carbonyl, and alkyl groups in plant compounds, while XRD confirmed the monoclinic crystalline structure of CuoNp. SEM images displayed disorganised, porous nanoparticles, with elemental composition verified by EDS. The biological properties of the synthesised CuONP were evaluated through various assays. The nanoparticles effectively inhibited α-amylase, suggesting potential anti-diabetic activity. Anti-inflammatory effects were demonstrated using bovine serum albumin and egg albumin denaturation assays, which showed dose-dependent reduction compared to the standard. The DPPH radicalscavenging assay revealed strong antioxidant activity, surpassing the standard at higher concentrations. Antimicrobial tests indicated mild inhibition against S. aureus, E. coli, Pseudomonas, and Candida albicans. Cytotoxicity assessment via the brine shrimp lethality assay demonstrated excellent biocompatibility at lower concentrations and mild toxicity at higher doses. CuONP synthesised with Hibiscus rosa-sinensis show promising antioxidant, anti-inflammatory, antidiabetic, and mild antimicrobial properties, highlighting their potential for biomedical and medicinal applications.