Valorization of Banana Peel Extract for Green Synthesis of Silver Nanoparticles: Physicochemical Characterization and Antibacterial Performance

Abstract

The growing demand for sustainable nanomaterial synthesis has driven interest in plant-mediated approaches that align with circular economy principles. This study presents a facile approach for generating silver nanoparticles (AgNPs) using Saba banana peel extract (Musa acuminata × balbisiana) as reducing and stabilizing agents. AgNPs were synthesised by reacting different ratios (1:1–1:12) of banana peel extract (BPE) with silver nitrate (AgNO₃, 1 mM) at 90°C for 2 h. Based on the UV-Visible spectra, the optimal BPE:AgNO₃ ratio was identified at 1:11. Fourier-transform infrared (FTIR) spectroscopy revealed that functional groups in the extract including hydroxyl, carbonyl and amine, were involved in the reduction of silver ions. Morphological analyses using Scanning electron microscopy (SEM) and Transmission Electron Microscopy (TEM) show the formation of spherical AgNPs with average size of 5.37 ± 1.36 nm, while energy-dispersive X-ray (EDX) analysis indicated a high silver content (73.87 wt%). The biosynthesised AgNPs displayed potent antibacterial activity against Staphylococcus aureus and Escherichia coli. These findings highlight the potential of Saba banana peel, an abundant and underutilized biomass, as a low-cost and sustainable resource for the green synthesis of AgNPs with promising antimicrobial properties and potential applications in biomedical, environmental, food and energy sectors.