Abstract

GREEN SYNTHESIS AND CHARACTERIZATION OF COPPER NANOPARTICLES USING AZADIRACHTA INDICA LEAF EXTRACT

G. Praveen Kumar, M. Dikshapriya, M. Rithika, C. Kalki, G. Kanimozhi, Dr. M. Senthil Raja, Dr. Pitta. Sriram Charan^*

Abstract

The present study investigates the green synthesis, characterization, and biological activities of copper nanoparticles (CuNPs) synthesized using Azadirachta indica (neem) leaf extract. Green synthesis of nanoparticles has gained considerable attention as an eco-friendly, economical, simple, and sustainable alternative to conventional chemical and physical methods that may involve toxic reagents, high energy consumption, and hazardous by-products. Fresh A. indica leaves were collected, washed, dried, and used to prepare an aqueous leaf extract. The phytochemicals present in the extract acted as natural reducing and stabilizing agents during the synthesis of CuNPs. The formation of nanoparticles was initially indicated by a visible colour change in the reaction mixture. The synthesized CuNPs were subsequently purified, dried, and characterized using UV–Visible spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and microscopic techniques such as Scanning Electron Microscopy (SEM) and/or Transmission Electron Microscopy (TEM). These analyses were used to determine the optical properties, functional groups, crystalline structure, morphology, and particle size of the synthesized nanoparticles. Furthermore, the biological activities of the CuNPs were evaluated using appropriate in-vitro antimicrobial and antioxidant assays. The antimicrobial activity was assessed against selected bacterial and/or fungal strains, while antioxidant potential was determined using suitable free-radical-scavenging assays. Appropriate controls were included for comparison. The study highlights the potential of A. indica leaf extract as an effective natural source for the synthesis and stabilization of CuNPs. The synthesized nanoparticles may possess promising biological activities and potential applications in pharmaceutical, biomedical, agricultural, and environmental fields, supporting the development of safer and more sustainable nanomaterial synthesis approaches.

Keywords: Green synthesis; Copper nanoparticles; Azadirachta indica; Nanotechnology; Antimicrobial activity; Antioxidant activity.