基于G-四联体的纳米探针比色检测铅离子

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.

Colorimetric Detection of Pb2+ Based on G-Quartet Structure by Nanoprobes

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 na-noprobes 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 effectively 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%).