Biogenic Approach using Sheep Milk for the Synthesis of Platinum Nanoparticles: The Role of Milk Protein in Platinum Reduction and Stabilization

Bio-directed synthesis of nanoparticles is an interesting field of rapid advancement for biologists, chemists and materials scientists, especially in light of efforts to find out green methods of inorganic material synthesis. In the present study, green synthesis of platinum nanoparticles (PtNPs) using sheep milk is reported for the first time. By adjusting the concentrations of chloroplatinic acid (H2PtCl6) and milk in aqueous solutions, spherical PtNPs were obtained at room temperature. The nanoparticles obtained were characterized by UV-Vis spectroscopy, dynamic light scattering (DLS), high-resolution Transmission Electron Microscopy (TEM) and X-Ray diffraction (XRD). The spherical particles obtained have an average size 9.0 nm as shown by XRD pattern and TEM analysis. Fourier Transform Infra-Red (FTIR) measurements were carried out to identify the possible biomolecules responsible for capping and efficient stabilization of the PtNPs synthesized by milk. The carboxylic acid group libration and amide I and II bands revealed the binding of protein with platinum surface through the amine group rather than the carboxyl group. Among a wide variety of biological resources which are introduced for reducing Pt ions into PtNPs, green approaches like using sheep milk have outstanding benefits for synthesize biological metal nanoparticles due to their eco-friendly phenomenon and very less amounts of cytotoxicity. PtNPs green synthesized in this study are potential candidates to use in drug discovery and gene transfer technologies.