探索利用无机结合肽PT2(DRTSTWR)制备纳米铂晶体

Exploiting Preparation of Platinum Nanocrystals with Peptide PT2 (DRTSTWR)

实验中首先利用固定化于PET(聚对苯二甲酸己二醇酯)膜上无机结合肽PT2(DRTSTWR)制备出铂微晶体.然后用游离的PT2与PtCl4在室温和pH中性环境中反应24h,所得产物用TEM观察,其多数为1～2nm呈方形和球形晶体,经EDX分析显示晶体的元素组成中Pt远大于Cl的含量,显然晶体不可能是PtCl4或PtCl2;样品的XPS谱图中出现了结合能值为71.0eV峰(Pt4f标准值71.1eV),确认晶体为铂纳晶,由此推断无机结合肽PT2在无细胞状态下能够作为模板仿生合成铂晶体.继而在反应体系中加入不同浓度的壳聚糖和聚丙烯酸钠,观察到纳米粒子的粒径和形貌随表面活性剂的加入发生了改变.加入5倍的壳聚糖制备的铂晶体的直径在12～15.5nm之间,晶体排布似乎有成线状的趋势.加入5倍的聚丙烯酸钠制备的铂晶体,形貌更加规整,以球形颗粒为主,粒子直径在6～8nm之间.

The synthesized peptide PT2 （DRTSTWR） has been employed as template for preparation of platinum nanoparticles. Platinum crystallites were obtained by the way of PtCh 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 PtC14 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. Especial/y, 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 Pt4＋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.