无标记增强型检测Hg^(2+)的荧光DNA传感器

A label-free enhanced fluorescence DNA biosensor for Hg^(2+) detection

基于Hg2+与T–T错配碱基对能特异性结合形成T-Hg2+-T结构以及结晶紫(CV)与单、双链DNA作用后荧光信号的差异,构建了一种荧光增强型检测Hg2+的DNA生物传感器。实验考察了不同序列DNA及溶液的pH、DNA与CV浓度比、稳定时间等因素对灵敏度的影响。在优化的条件下体系荧光效率和Hg2+浓度在2～40 nmol/L范围内呈良好的线性关系,检出限为0.7 nmol/L。并且高浓度的Ca2+,Mg2+等常见金属离子对Hg2+的检测没有干扰。方法为重金属Hg2+的检测提供了一个较好的荧光分析方法。

A label-free signal-on＇fluorescence biosensor for detection of mercury （ Ⅱ ） in an aqueous solution is reported. This biosensor is based on the specific interaction of Hg2＋ with T-T mismatched base pairs and the fluorescence signal differences between ssDNA and dsDNA with crystal violet （CV）. The influence factors on detection sensitivity, such as different sequences of DNA, pH, DNA/CV concentration ratio, stability time and so on, have been discussed. Under the optimum experimental conditions, the system fluorescence intensity gave a lanear response to the concentration of Hg2＋ in a range from 2 to 40 nmol/L. The detection limit for Hg2＋ was 0. 7 nmol/L. We also found that even at high concentration, the common metal cations such as Ca2＋ , Mg2＋ in the system had no impact on the detection of Hg2＋. It can provide a good fluorescence analysis method for the detection of Hg2＋ in the heavy metal polluted environment.