Green Synthesis of Silver Nanoparticles Using Megalaspis Cordyla Scutes: Characterization and Biological Activity

Fish processing industry generates substantial waste, including fish scales, creating environmental and disposal challenges. This study aimed at valorization of Megalaspis cordyla scutes for green synthesis of silver nanoparticles (AgNPs) with antimicrobial and cytotoxic activity. An aqueous extract of M. cordyla scutes were used as a natural reducing and stabilizing agent for AgNP synthesis. The Megalaspis cordyla scutes silver nanoparticles (MSEAgNPs) were characterized using UV–Visible spectroscopy, FESEM–EDX, TEM–SAED, DLS, zeta potential, and ATR–FTIR. The MSEAgNPs were assessed for antimicrobial activity using agar well diffusion (alone or in combination with streptomycin or clotrimazole) and minimum inhibition concentration against E. coli, S. aureus and C. albicans, and for in vitro cytotoxicity against MCF-7 breast cancer cells. The MSEAgNPs exhibited crystalline spherical structure with size range from 6–12 nm, a distinct surface plasmon resonance at ~430 nm, and long-term structural stability (>1 year). The FTIR analysis indicated collagen-mediated reduction and surface stabilization. The nanoparticles demonstrated concentration-dependent antimicrobial activity against Escherichia coli, Staphylococcus aureus, and Candida albicans. The MSEAgNPs showed a dose-dependent cytotoxicity against MCF-7 breast cancer cells. This study demonstrates an eco-friendly valorization of scutes of M. cordyla for synthesis of stable multifunctional AgNPs. Our findings highlight the potential of MSEAgNPs as antimicrobial agents and valorization of fish processing waste as a viable resource for circular bioeconomy.