金铂纳米合金催化磷钼蓝光度法测定半胱氨酸

AuPt Nanoalloy Catalytic Phosphomolybdate Blue Spectrophotometric Assay for Cysteine

在pH2.8HCOOH-HCOONa缓冲溶液中,半胱氨酸(Cys)可与金铂纳米粒子(AuPtNP)作用发生聚集,导致深红色的金铂纳米微粒变成蓝紫色。AuPtNP对甲酸还原磷钼酸生成磷钼蓝反应具有较强的催化作用,而金铂纳米粒子聚集体(AuPtNPA)的催化作用较弱。随着Cys浓度增大,体系中AuPtNPA增多,而AuPtNP减少,催化能力随之减弱,磷钼蓝在700nm处的吸光度值降低,Cys浓度在30～350nmol/L与其吸光度降低值ΔA呈良好的线性关系,检测限为28nmol/L,表观摩尔吸光系数为1.8×106L·mol-1·cm-1。据此建立了测定半胱氨酸的纳米金铂催化光度分析新方法。

In the pH 2. 8 HCOOH-HCOONa buffer solution,the cysteine（Cys） interacted with gold-platinum nanoparticles （AuPtNP） to form aggregations that resulted in its color changing from wine red to blue-violet. The AuPtNP has a strong catalysis on the phosphomolybdate blue reaction of formic acidphosphomolybdic acid,but the AuPtNP aggregations （AuPtNPA） catalysis is weak. With the increase of Cys concentration,the AuPtNPA increased and the AuPtNP decreased,the catalysis decreased and the absorption value of phosphomolybdate blue at 700 nm decreased. The Cys concentrations in the range of 30~350 nmol/L had good linear response to the decreased absorption value AA,with a detection limit of 28 nmol/L, and its molar absorption coefficients was 1. 8 × 106^6 L · mo1^-1 · cm^-1. Thus, a new nanocatalytic spectrophotometric method is established for the determination of Cys.