苝酐衍生物功能化空心纳米金电致化学发光铅离子传感器的研究

Electrochemiluminescence Biosensor Based on DNAzyme and 3,4,9,10-Perylenetetracarboxylic Dianhydride Derivative Functionalized Hollow Gold Nanoparticles for Detection of Lead Ions

基于目标物循环放大策略及苝酐衍生物功能化纳米探针,构建了超灵敏的电致化学发光（ECL）传感器用于Pb2＋检测。将发卡型DNA底物链通过分子自组装固载于沉积纳米金的玻碳电极表面,当目标物Pb2＋及脱氧核酶（DNAzyme）存在时,底物链被剪切,在电极上留下单链DNA,同时释放出的Pb2＋和DNAzyme可进入下一个循环,继续对未剪切的底物链进行剪切。剪切得到的单链DNA可与辅助探针H1的一端杂交,H1的另一端可与标记有苝酐衍生物功能化空心纳米金的发夹探针H2杂交。随着Pb2＋浓度的增加,更多的信号探针被捕获,使得电极上产生的ECL信号逐渐增强。在Pb2＋不存在时,底物链不能被剪切,信号探针不能被捕获,ECL信号低。本传感器在1×10-12~1×10-6mol/L的浓度范围内对Pb2＋有良好的线性响应,检出限为1×10-12mol/L（S/N=3）。传感器对常见的金属离子表现出良好的选择性。

Based on target cycling amplification and 3,4,9,10-perylenetetracarboxylic dianhydride derivative functionalized singal probe,an ultrasensitive electrochemiluminescence（ ECL） sensor was designed for the detection of lead ions. The hairpin substrate DNA was immobilized on the electrode through molecular selfassembly. In the presence of Pb2＋and DNAzyme,the substrate was cleaved with single strand DNA fragments left on the electrode surface. Meanwhile,the target and DNAzyme was released for another cleaving circularly.As a result,the single strand DNA fragments hybridized with the assist hairpin probe H1,which leaded to the fabrication of H2 labeled with the 3,4,9,10-perylenetetracarboxylic dianhydride derivative functionalized hollow gold nanoparticles. With the increasing concentration of Pb2＋,much more signal probe was been captured and the ECL signal of the biosensor in peroxydisulfate（ S2O2-8） solution would increase. An ECL assay demonstrates that the sensor has a good linear response to Pb2＋concentration in the range of1×10-12mol / L-1×10-6mol / L,with a detection limit of 1 × 10-12mol / L. The fabricated sensor shows good selectivity toward Pb2＋against other common metal ions.