Protein-mediated synthesis of gold nanoparticles

Our current approach is to synthesize gold nanoparticles utilizing Serrapeptase that serves as both a reducing and stabilizing agent. The investigations further reveal that certain amino acid groups like lysine are involved in reduction and stabilization of these particles. The particles are characterized with UV-vis spectroscopy. Transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, Proton Nuclear Magnetic Resonance (H NMR) Spectroscopy studies and Sodium dodecyl sulphate-polyacrylamide gel electrophoresis for Serrapeptidase and Au-Serrapeptidase isolation. Transmission electron microscopy studies show particles ranging from 20 nm to 200 nm that are spherical, hexagonal and polygonal in nature. UV-vis spectroscopy shows surface plasmon band at 536 nm that indicates formation of spherical particles whereas, results further add that gold particles are formed inside the nanosphere that is stabilized by interaction of amino acid groups like gamma-lysine of peptase. Fourier transform infrared spectroscopy studies reveal that few carboxyl groups are involved during the synthesis process followed by stretching of -CH bonds which has been seen in the case of lysine of Serapeptase. Current studies therefore show that the method utilized for the synthesis of Au-nanoparticles is a biofriendly method and the nanogold formed can be a useful attribute for various applications. (C) 2009 Elsevier B.V. All rights reserved.