L-色氨酸-Hg^(2+)-青霉胺体系的荧光光谱及分析应用

Fluorescence Spectra and Analytical Applications of L-tryptophan-Hg^(2+)-penicillamine System

基于L-色氨酸(L-Trp)荧光猝灭与恢复,建立了一种高灵敏度、高选择性检测D-青霉胺(D-PA)的荧光分析方法.实验发现在pH=4.8的缓冲溶液中,Hg^(2+)与L-Trp中的羧基结合,猝灭L-Trp的荧光.随着D-PA的加入,由于Hg^(2+)与D-PA的巯基产生更强的螯合作用,导致Hg^(2+)脱离L-Try,后者荧光恢复.据此设计了IMPLICATION逻辑门,并用于D-PA的检测.在优化条件下,荧光恢复程度与D-PA浓度在0.44~50.0μmol/L范围内呈良好的线性关系,检出限为0.13μmol/L.该方法用于青霉胺药片含量的测定,结果满意.

A highly sensitive and selective fluorescence method for detection of D-penicillamine(D-PA)was designed based on the“OFF-ON”fluorescence switch mode of L-tryptophan(L-Trp).The fluorescence of L-Trp turned OFF due to the effective reaction between carboxyl group of L-Trp and Hg^(2+) in pH 4.8 BR buffer.The thiol group in D-PA could compete with L-Trp for chelating Hg^(2+),which turned ON the fluorescence of L-Trp.An IMPLICATION logic gate was designed and used for D-PA detection.Under optimized conditions,a good linear relationship was shown between fluorescence recovery and D-PA concentration in range of 0.44-50.0μmol/L with the detection limit of 0.13μmol/L.The method was used for the determination of D-PA in medicine with satisfactory results.