eng Oriental Scientific Publishing Company Biosciences Biotechnology Research Asia 0973-1245 2025-12-30 22 4 1746 1754 10.13005/bbra/3473 57200 article Naveen Vijayakumar 1 Asbin Mary Xaviour Raja Mani 1 Department of Biotechnology, Alpha College of Arts and Science, Chennai, India. An environmentally responsible and sustainable substitute for traditional chemical and physical processes is the biogenic production of silver nanoparticles (AgNPs). With a focus on green chemistry, this study investigates the use of collagen obtained from fish as a capping and reducing agent for the synthesis of AgNPs. Acid-solubilization and enzymatic hydrolysis were used to separate collagen from fish skin of Oreochromis niloticus. The Type II collgen was then confirmed by characterization using SDS-PAGE and Western Blotting methods. The silver nanoparticles tagged collagen were synthesized using leaves of Psidium guajava. The optical characteristics, functional group interactions, and shape of the produced silver nanoparticles were assessed using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and UV-Vis spectroscopy. The findings showed that collagen-derived functional groups stabilized well-dispersed, spherical AgNPs with an average diameter in the nanoscale range of 180–210 nm. The study emphasizes the dual function of fish collagen as a stabilizing agent and biotemplate, providing a sustainable pathway for the synthesis of nanoparticles and encouraging the value-adding of marine byproducts. This thorough study opens the door for collagen-mediated AgNPs to be used in wound healing, biomedicine, and antibacterial applications in the future. https://www.biotech-asia.org/vol22no4/fish-collagen-based-biogenic-synthesis-of-silver-nanoparticles-an-extensive-investigation-into-extraction-capping-and-characterization/ Characterisation; Collagen-mediated AgNPs; Oreochromis niloticus; Psidium guajava; Wound healing