基于G-四联体的纳米探针比色检测铅离子

Colorimetric Detection of Pb^(2+) Based on G-Quartet Structure by Nanoprobes

基于纳米探针和G-四联体建立了简便快速检测铅离子的方法.纳米探针采用金纳米粒子自组装修饰富G寡核苷酸制得,在铅离子存在下,纳米探针上的富G寡核苷酸形成G-四联体,导致纳米探针凝聚变色.在优化条件下,比色检测铅离子的线性范围为48～480 nmol/L,检出限为20 nmol/L;大多数金属离子无明显干扰,而有明显干扰的汞离子可采用与之特异结合的寡核苷酸有效消除.将该法成功用于环境水样中铅离子的检测,重现性(RSD<3.0%)与回收率(98.4%～101.5%)良好.

A simple and sensitive detection method for lead ions was developed,based on the G-quartet and nanoprobe.The nanoprobe was prepared by modification of gold nanoparticles with G-rich oligonucleotides in a self-assembled way.In the presence of Pb2 ＋,G-quartets are formed by G-rich oligonucleotides on the nanoprobes and result in the aggregation of nanoprobes and a change in color.Under the optimal condition of 200 mmol/L NaCl,2.0 mmol/L MgCl2 and at 37 ℃,the linear range was 48—480 nmol/L with a detection limit of 20 nmol/L for Pb2 ＋.Most metal ions have no interferences,and the interfering Hg2 ＋ can be effective-ly eliminated by a specific oligonucleotide.This method was applied for the detection of Pb2 ＋ in environmental water samples,with a good reproducibility（RSD 3.0%） and recovery（98.4% —101.5%）.