【作者】 黄红云； 王丽军； 田建袅；

【Author】 Hongyun Huang;Lijun Wang;Jianniao Tian;School of Chemistry and Pharmaceutical Science of Guangxi Normal University;

【机构】 广西师范大学化学与药学学院；

【摘要】 半胱氨酸（Cys）是一种含巯基的氨基酸,在生物体内的含量水平与艾滋病等多种疾病相关。因此,有必要对其进行灵敏检测。据报道,分散的金纳米粒子（AuNPs）和CdTe量子点（QDs）之间能够发生荧光共振能量转移（FRET）,而生物巯基和氨基能强烈结合AuNPs^[1,2]。基于此,本文构建了一种AuNPs和CdTe QDs的FRET方法检测Cys。检测原理如图1所示,体系中无Cys的情况下,AuNPs处于分散状态,能有效猝灭CdTe QDs荧光;当存在Cys时,Cys与AuNPs结合,而Ca²⁺又能与Cys以1:2的比例键合,促使AuNPs进一步聚集,从而降低AuNPs与CdTe QDs之间的FRET效率,使CdTe QDs荧光恢复。且Cys本身也能增强CdTe QDs荧光,进一步增强信号值。如图2所示,本方法的线性范围是1-30μmol·L^-1,检测限是0.528μmol·L^-1。本实验提供了一种无酶、免标记,简单快速检测半胱氨酸的荧光分析方法。更多还原

【Abstract】 Cysteine is well known as an amine acid with a thiol.It plays a significant role in the biosystem because of the relationship to kinds of disease.Herein,we have developed a method for cysteine detection based on the the Forster Resonance Energy Transfer（FRET） between CdTe Quantum Dots（QDs）and gold nanoparticles（AuNPs）.The simultaneous addition of cysteine and Ca²⁺ to AuNPs colloidal solution results in the cross-linking of the AuNPs,leading to the aggregation of AuNPs.So the efficiency of fluorescence quenching of the QDs by the AuNPs through FRET was decreased mostly.While cysteine was absent,AuNPs was dispersed and could quench the fluorescence of CdTe QDs efficiently.The fluorescent intensity was in proportion to the concentration of cysteine within 1-30μmol·L^-1.The proposed manner reached a detection limit of ⁰.528 μmol·L^-1,providing the superiorities in label-free and enzyme-free reaction procedure.更多还原