Du Ping, Li Hongxia, Mei Zhenhua, Liu Shufeng
Key Laboratory of Eco-chemical Engineering, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China.
Bioelectrochemistry. 2009 Apr;75(1):37-43. doi: 10.1016/j.bioelechem.2009.01.003. Epub 2009 Jan 27.
In this article, colloidal gold nanoparticles (Au NPs) and carboxyl group-functionalized CdS Nanoparticles (CdS NPs) were immobilized on the Au electrode surface to fabricate a novel electrochemical DNA biosensor. Both Au NPs and CdS NPs, well known to be good biocompatible and conductive materials, could provide larger surface area and sufficient amount of binding points for DNA immobilization. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) experiments were performed to follow the whole electrode fabrication process. DNA immobilization and hybridization were characterized with differential pulse voltammetry (DPV) by using [Co(phen)(2)(Cl)(H(2)O)]Cl.2H(2)O as an electrochemical hybridization indicator. With this approach, the target DNA could be quantified at a linear range from 2.0x10(-10) to 1.0x10(-8) M, with a detection limit of 2.0x10(-11) M by 3sigma. In addition, the biosensor exhibited a good repeatability and stability for the determination of DNA sequences.
在本文中，将胶体金纳米颗粒（Au NPs）和羧基官能化的硫化镉纳米颗粒（CdS NPs）固定在金电极表面，以制备一种新型的电化学DNA生物传感器。众所周知，Au NPs和CdS NPs都是良好的生物相容性和导电材料，它们可为DNA固定提供更大的表面积和足够数量的结合位点。采用循环伏安法（CV）和电化学阻抗谱（EIS）实验来跟踪整个电极制备过程。通过使用[Co(phen)(2)(Cl)(H(2)O)]Cl.2H(2)O作为电化学杂交指示剂，利用差分脉冲伏安法（DPV）对DNA固定和杂交进行表征。通过这种方法，目标DNA的定量线性范围为2.0×10(-10)至1.0×10(-8) M，3σ检测限为2.0×10(-11) M。此外，该生物传感器在DNA序列测定中表现出良好的重复性和稳定性。
