摘要
以可卡因适体为分子识别物,CdS量子点为检测物,制备了一种新型灵敏的电化学可卡因适体传感器。首先将巯基化的可卡因适体固定到金纳米颗粒修饰的玻碳电极,将CdS量子点标记到合成DNA,再与可卡因适体互补的DNA同时结合在金纳米颗粒上,通过可卡因适体与互补DNA碱基配对连接到电极。当向溶液中加入可卡因时,由于可卡因与可卡因适体的结合能力强于碱基对之间的结合力,使得CdS脱落下来,通过溶出伏安法检测Cd2+的溶出峰电流来实现对可卡因的间接测定。通过金纳米粒子的信号放大作用,提高了传感器的灵敏度。线性范围为1.0×10-10～5.0×10-8mol·L-1,检出限为4×10-11mol·L-1。
An electrochemical novel sensitive aptasensor for determination of cocaine was prepared based on CdS quantum dots in this paper.The signal was amplified through gold nanoparticles to further improve the sensitivity of the experiment.Thiolated cocaine aptamers are self-assembled on gold nanoparticles-modified electrode for fabricating onto AuNPs together with capture DNA complementary aptamer-sensor.Synthesized DNA was labeled with CdS quantum dots and conjuncated with cocaine aptamer.Au-NPs conjucate were linked to the electrode through hybrid with cocaine aptamer.With the introduction of cocaine,the aptamer parts bound with their targets and folded to the complex structures.As a result,AuNPs linked with CdS quantum dots were released into solution.The CdS quantum dots were measured by stripping voltammetry,and the concentrations of cocaine were proportional to the signal of Cd2＋ ion.With the amplification of AuNPs and preconcentration of Cd2＋ through stripping voltammetry technology,cocaine could be quantified over the ranges from 1.0×10-105.0×10-8mol·L-1 with a detection limit of 4×10-11mol·L-1.This method is simple,quick and sensitive.
出处
《云南化工》
CAS
2010年第5期1-6,共6页
Yunnan Chemical Technology
基金
国家自然科学基金项目(No.20865006)
云南省自然科学基金项目(No.2006B0028M)
关键词
量子点
可卡因
适体传感器
金纳米颗粒
差分脉冲伏安法
quantum dots
cocaine
aptamer
sensor
gold nanoparticles
differential pulse vohammetry
