Bioreduction mechanism of silver nanoparticles

Area of Science:

• Biotechnology and Nanotechnology
• Microbiology
• Materials Science

Background:

• Investigating novel bioreduction mechanisms for silver nanoparticle (Ag NP) synthesis.
• Exploring the role of bacterial species in nanoparticle formation.
• Understanding the surface chemistry and capping agents of biosynthesized Ag NPs.

Purpose of the Study:

• To synthesize silver nanoparticles (Ag NPs) using Bacillus subtilis spizizenni (NCIM 2063).
• To elucidate the detailed bioreduction mechanism of Ag NP synthesis.
• To evaluate the antibacterial efficacy of the synthesized Ag NPs.

Main Methods:

• Synthesis of Ag NPs using Bacillus subtilis.
• Characterization using Optical absorption spectroscopy, FT-IR, XRD, and TEM.
• Mechanism elucidation via Sephadex G-25 chromatography, HR-LCMS, nitrate reductase assay, and HR-MS for capping agent detection.

Main Results:

• Ag NPs exhibited surface plasmon resonance between 408-423 nm.
• FT-IR confirmed N-H groups on Ag NP surfaces; XRD indicated face-centered cubic and hexagonal structures.
• Nitrate reductase, bacterial enzymes, and specific tripeptides (TYK, PFF, YIF, RWE) were identified as key components in the bioreduction and capping processes.

Conclusions:

• A detailed bacterial-mediated bioreduction mechanism for Ag NP synthesis by Bacillus subtilis was established.
• The study identified specific enzymes and tripeptides responsible for Ag NP formation and stabilization.
• Synthesized Ag NPs demonstrated antibacterial activity, presenting a cost-effective and environmentally friendly alternative to conventional methods.