The synthesized peptide PT2 (DRTSTWR) has been employed as template for preparation of platinum nanoparticles. Platinum crystallites were obtained by the way of PtCl₄ reacting with PT2 immobilized on the surface of protonated PET-N(CH₃)₂ film. The platinum nanoparticles ranging from 1 to 2 nm in size were obtained with the free PT2 and PtCl₄ mixed together in a solution at room temperature and pH 7 for 24 h. Both the crystallites and nanoparticles of platinum were characterized by TEM, XPS and EDX. Based on the data above, it was confirmed that PT2 could be utilized as a template for biomimetic synthesis of platinum nanoparticles in vitro. Subsequently, in order to prepare shape and size controllable nanoparticles of platinum, chitosan and sodium polyacrylate with different concentrations were added into the reaction solution respectively, resulting in the variation of the size and shape of the platinum particles. Especially, platinum particles with size ranging from 12 to 15.5 nm which inclined to array in line were obtained when the molar ratio of chitosan to Pt^4＋was 5/1 in the solution. In the presence of sodium polyacrylate whose amount was 5 times of Pt^4＋, more uniformly spherical platinum particles with size of 6 to 8 nm were synthesized.

Key words: inorganic binding peptide, platinum nanoparticle, stabilizer, controllable synthesis