金纳米微粒表面能量转移及半胱氨酸的高灵敏度高选择性分析法  

Gold nanoparticles surface energy transfer and its application to highly selective and sensitive detection of cysteine

作　　者：刘春[1,2] 吴同[1,2] 黄承志[1,2,3] 

机构地区：[1]发光与实时分析教育部重点实验室 [2]西南大学化学化工学院,重庆400715 [3]西南大学药学院,重庆400715

出　　处：《中国科学：化学》2010年第5期531-537,共7页SCIENTIA SINICA Chimica

基　　金：国家自然科学基金(90813019)资助

摘　　要：根据荧光染料在金纳米粒子表面的能量转移,本文建立了一种具有高灵敏和高选择性半胱氨酸分析方法.研究表明,通过静电作用吸附在柠檬酸根包被的金纳米粒子表面的阳离子荧光染料如罗丹明B分子在受光激发时,发生从荧光染料到金属纳米微粒的能量转移,导致荧光染料的荧光猝灭.但当体系中存在半胱氨酸时,由于半胱氨酸与金纳米粒子之间具有更强的共价作用,罗丹明B分子远离金纳米粒子表面,降低了能量转移效率,使得罗丹明B的荧光得到恢复.恢复的荧光强度与0.025～4.5μmol/L半胱氨酸呈很好的线性关系,检测限为8.0nmol/L(3σ),而其他十九种基本氨基酸的响应非常微弱.In this contribution,we report a highly selective and sensitive method for detecting cysteine based on surface energy transfer from fluorophore to gold nanoparticles.Cation dyes,such as Rhodamine B,can be adsorbed onto the surface of citrated-gold nanoparticles through the electrostatic interaction,and the fluorescence of the Rhodamine B absorbed on the surface of the as-prepared gold nanoparticles gets quenched because of the occurrence of surface energy transfer from the fluorophore of Rhodamine B to the gold nanoparticles.With the addition of cysteine,the strong covalent combination between the mercapto group of cysteine and gold nanoparticles drives Rhodamine B molecules apart from the gold nanoparticles＇ surface,which reduces the energy transfer efficiency and results in a significant increase of fluorescence of the solution.It was found that the fluorescence gets increased linearly with the concentration of cysteine ranging from 0.025 μmol/L to 4.5 μmol/L.This phenomenon allows sensitive detection of cysteine with a detection limit of 8.0 nmol/L （3σ）.Other 19 kinds of natural amino acids have a weak influence on the surface energy transfer.

关 键 词：荧光染料 罗丹明B 金纳米粒子 表面能量转移(SET) 半胱氨酸 

分 类 号：O657.3[理学—分析化学]