College of Materials, Chemistry and Chemical Engineering, Chengdu University of Technology, Chengdu, Sichuan 610059, PR China.
College of Materials, Chemistry and Chemical Engineering, Chengdu University of Technology, Chengdu, Sichuan 610059, PR China.
Biosens Bioelectron. 2015 Sep 15;71:194-199. doi: 10.1016/j.bios.2015.04.038. Epub 2015 Apr 14.
In this study, a sensitive electrochemiluminescent (ECL) biosensor for the detection of Hg(2+) was easily prepared by self-assembling mercury-specific oligonucleotide on the surface of gold nanoparticles (AuNPs) modified indium tin oxide (ITO) electrode. A conformation change of the oligonucleotide from linear chain to hairpin occurs upon the binding of Hg(2+) through thymine-Hg(2+)-thymine coordination. The dual-function oligonucleotide serves as the probe to Hg(2+) but also a carrier of signal-generating molecules, Ru(bpy)2(dppz)2. It was estimated that one oligonucleotide was able to load with eight ECL signal molecules; a ratio of four or five oligonucleotides per gold nanoparticle was obtained basing on the calculation with surface density. Without tedious multiple-labeling procedures and special modification of oligonucleotide probe for signal transduction/amplification, a detection limit of 5.1 pM Hg(2+) was outstanding from the interference of other ten metal ions. Results of spiked water samples were in good agreement with that obtained by atomic fluorescent spectrometry.
在这项研究中，通过将汞特异性寡核苷酸自组装到金纳米粒子（AuNPs）修饰的氧化铟锡（ITO）电极表面，很容易制备出用于检测 Hg(2+) 的灵敏电致化学发光（ECL）生物传感器。当 Hg(2+) 通过胸腺嘧啶-Hg(2+)-胸腺嘧啶配位结合时，寡核苷酸从线性链到发夹构象发生变化。该双功能寡核苷酸既可用作用于 Hg(2+) 的探针，也可用作信号生成分子Ru(bpy)2(dppz)2 的载体。据估计，一个寡核苷酸能够负载八个 ECL 信号分子；基于表面密度的计算，每个金纳米粒子获得的寡核苷酸比例为四到五个。无需繁琐的多标记程序和寡核苷酸探针的特殊信号转导/放大修饰，与其他十种金属离子的干扰相比，Hg(2+) 的检测限达到了 5.1 pM。水样的加标结果与原子荧光光谱法的结果吻合良好。
