Synthesis of Copper Oxide Nanoparticles Using Garlic Peel Extract: Phytochemical Profiling, Evaluation of Antioxidant, Antimicrobial, and Anticancer Activities

Abstract

Garlic peel, an agricultural waste material, is a rich source of bioactive compounds and can serve as an eco-friendly resource for nanoparticle synthesis. The present study aimed to synthesise copper oxide nanoparticles using garlic peel extract and evaluate their phytochemical, antioxidant, antimicrobial, and cytotoxic activities. Phytochemical analysis confirmed the presence of six compounds, with high levels of alkaloids and flavonoids. Antioxidant activity was evaluated using DPPH radical scavenging and total phenolic content assays, and the synthesized copper oxide nanoparticles exhibited higher antioxidant activity than the aqueous extract. The synthesized copper oxide nanoparticles were characterised using UV–Visible spectroscopy, FTIR, SEM, HRTEM, zeta potential analysis, and XRD. The UV–Visible analysis showed an absorption peak at 290 nm, indicating nanoparticle formation. FTIR analysis confirmed the presence of phytoconstituents and hydroxyl groups that may contribute to nanoparticle stabilization. The morphology and size of the synthesized copper oxide nanoparticles were elucidated using SEM, while TEM confirmed spherical and cuboidal structures with sizes ranging from 10–40 nm. Zeta potential analysis indicated a negative surface charge, and XRD confirmed the crystalline nature of the synthesized sample. Furthermore, copper oxide nanoparticles exhibited antimicrobial activity and cytotoxicity against the A549 cell line, with an IC50 value of 155.21 µg/mL.