Bio-inspired synthesis of silver selenide (Ag₂Se) binary chalcogenide nanoparticles mediated by Punica granatum L. peel extract and a comprehensive evaluation of their biological activities

Abstract The growing threat of antibiotic-resistant bacteria calls for the urgent development of novel antimicrobial agents. Binary chalcogenide nanoparticles, particularly Ag2Se nanoparticles, have emerged as promising candidates due to their enhanced antibacterial properties, biocompatibility and multifunctional applications. This study presents an eco-friendly synthesis of Ag2Se nanoparticles using pomegranate (Punica granatum L.) peel extract, leveraging its rich polyphenols and flavonoids as natural reducing and stabilizing agents. The synthesized nanoparticles were characterised using UV-Vis spectroscopy, FTIR, XRD and FE-SEM, confirming successful synthesis, different bonds and functional groups and their structural and morphological properties. The average crystalline size of Ag2Se nanoparticles determined to be 11.52 nm. DLS and zeta potential analysis revealed that Ag2Se nanoparticles of size 282.1 nm were stable in nature. Antimicrobial assays demonstrated potent activity against both Gram-positive (Staphylococcus aureus with 100 µg/mL MIC, Staphylococcus epidermidis with 250 µg/mL MIC) and Gram-negative (Escherichia coli with 100 µg/mL MIC, Acinetobacter baumannii with 250 µg/mL MIC) bacteria, achieving upto ~ 95%-100% inhibition at 500 µg/mL with significant membrane disruption observed through cytoplasmic leakage and SEM analysis. Additionally, the Ag2Se nanoparticles exhibited notable antioxidant activity in DPPH with an IC50 of 142.6 µg/mL, and H2O2 assays with 158.3 µg/mL, alongside < 5% hemolysis at 25 µg/mL concentration. These findings highlight the dual functionality of Ag2Se nanoparticles as effective antimicrobial and antioxidant agents, offering sustainable solutions for biomedical applications such as wound healing, antimicrobial coatings and drug delivery systems. This green synthesis approach aligns with global efforts towards eco-friendly nanotechnology.