A Cost-Effective Method to Prepare Gold Nanoparticles from Pomegranate Fruit Peel; Assessing their in vitro Pharmacological Activity

Abstract

A rapid, eco-friendly, and cost-effective green synthesis route was established for the fabrication of gold nanoparticles (Au NPs) utilizing aqueous extracts derived from Punica granatum L. (pomegranate) agricultural peel waste, thereby valorizing agro-industrial by-products. The proposed method eliminates the need for hazardous reducing agents and external stabilizers, offering a fully biogenic and waste-to-value nanomanufacturing approach. The synthesized AuNPs were extensively characterized using UV–Vis spectroscopy, FTIR, XRD, TEM, STEM, DLS, zeta potential analysis, and EDX, confirming the formation of crystalline, spherical, and highly stable nanoparticles with a surface plasmon resonance peak at 532.3 nm, an average hydrodynamic diameter of 47.1 nm, and a zeta potential of −16.2 mV. The integration of multiple complementary analytical techniques further validated the structural and colloidal stability of the nanostructures. The AuNPs exhibited strong, dose-dependent antimicrobial activity against pathogenic microorganisms and significant cytotoxic effects against human cancer cell lines in vitro. The novelty of this work lies in the dual contribution of (i) transforming agricultural waste into a functional nanomaterial platform and (ii) producing biologically active AuNPs via a single-step, green, and scalable synthesis route without chemical additives.