Fabrication and Characterization of pH-Mediated Labeo rohita Fish Scale Extract Capped Silver Nanoparticles and its Antibacterial Activity

The present study was designed to the synthesis of pH- responsive silver nanoparticles (AgNPs) by green route approach using Labeo rohita ( L. rohita ) fish scale aqueous extract. The synthesized AgNPs were optimized by various pH (5–9) ranges and characterized by Ultraviolet–Visible spectroscopy (UV–Vis), X-ray diffraction crystallography (XRD), Fourier transform infrared spectroscopy (FT-IR), Transmission electron microscopy (TEM), Zeta potential, and dynamic light scattering (DLS) analysis. Surface Plasmon Resonance (SPR) bands observed at 400–405 nm range in UV–Visible spectrum and this SPR band was preliminary confirmation of AgNPs synthesis. FT-IR spectral results show that different functional groups acted as definitive reduction and capping agents for the formation of AgNPs. Microscopy analysis confirm that AgNPs are spherical in shape with average particle size of 42.9 to 80.1 nm in range and confirmed that the 65.19% of Ag ions present in AgNPs by EDAX analysis. In addition, the antimicrobial activity of AgNPs revealed potential activity against different pathogens. Among those pathogens, Staphylococcous aureus showed higher zone of inhibition (8.2 ± 1.4 mm) at 100 μg/mL. In addition, S. aureus inhibition was proved by SEM morphological analysis, which indicates cell wall damaged. Overall, this present investigation confirms that green route AgNPs are potential source for biomedical applications.