Jornal de Nanomedicina e Nanotecnologia

Abstrato

Immobilization and Characterization of Purified Aspergillus flavus Peroxidase Mediated Silver Nanoparticle Synthesis: Peroxidase Surface Reactive Residues are Implemented for Reduction of Silver Ions, More than Its Active Sites

El-Sayed ASA, Rabie GH, El-Gazzar NS and Ali GS

Silver nanoparticles (AgNPs) have been used extensively in various therapeutic applications, molecular diagnostics. Chemical methods for synthesis of AgNPs are frequently used, however, the expenses and releases of toxic byproducts are the main limitations. Biological methods provide an alternative source for AgNPs synthesis for its cost and environmental safety. Fungi possess unique system for Ag+ resistance via secretion of multiple proteins for ions reduction to their nanoparticles. The objective of this study was to deciphered the mechanisms of Ag+ reduction to Ag0 by A. flavus. The synthesized AgNPs by A. flavus have molecular size ranged from 9-15 nm with visual molecular stability for abundance of stabilizing agents. A. flavus peroxidase was purified, immobilized on chitosan, polyacrylamide and sodium alginate, and biochemically characterized with strong potency for Ag+ reduction to AgNPs that are significantly stable (-30.6 mv) and UV-Vis analysis (A390 nm). The immobilized peroxidase has a significant operative stability for continuous production of AgNPs with homogenous molecular stability till the 5th catalytic cycle, emphasizing the efficiency of this technology for industrial scale synthesis of AgNPs. The reducing properties of peroxidase to Ag+ to AgNPs is mainly due to the protein functional surface reactive groups than the enzyme functional active sites. Scalingup potency and molecular stability of AgNPs produced by immobilized peroxidase provides a new feasible technical avenue for AgNPs exploitation.