利用L-半胱氨酸修饰的碳量子点作为荧光探针检测甘氨酸

Detection of Glycine Using L-Cysteine Modified Carbon Quantum Dots as Fluorescent Probe

甘氨酸是结构最为简单的氨基酸,以其为基石可以演变成各种复杂的人体所需的氨基酸,其本身不具有荧光特性。本文以柠檬酸为碳源,利用L-半胱氨酸作为修饰剂,合成了新的高荧光产率的碳量子点。经实验分析发现,合成的碳量子点的荧光能够被Pd(Ⅱ)显著猝灭,有趣的是,若在猝灭体系中加入适量的不具荧光特性的甘氨酸,可使猝灭的荧光恢复。基于碳量子点这种荧光"开-关"的模式,建立起一种快捷检测甘氨酸的新方法。在最优实验条件下,CDs-Pd(Ⅱ)体系检测甘氨酸的线性范围为9.0×10^(-7)~1.2×10^(-5)mol·L^(-1),检出限为1.1×10^(-7) mol·L^(-1)。

Glycine is the simplest amino acid in structure with any fluorescence property,it could be evolve into all kinds of complicated amino acids that needed by human body.In this work,the Carbon quantum dots with high fluorescence yield were synthesized using citric acid as carbon source and L-cysteine as a modifier.This study found that the fluorescence of Carbon quantum dots could be quenched by Pd（Ⅱ）,interestingly,the fluorescence can be recovered by adding Glycine without any fluorescence.Based on the fluorescence'on-off'model of carbon quantum dots,a new method for the detection of glycine was proposed.Under the optimum conditions,the recovered fluorescence intensity was linearly proportional to the increasing Glycine concentration in the range of 9.0×10-71.2×10-5 mol·L-1,and the detection limit was 1.1×10-7 mol·L-1.