Key Laboratory of Eco-chemical Engineering, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, China.
Biosens Bioelectron. 2010 Mar 15;25(7):1640-5. doi: 10.1016/j.bios.2009.11.026. Epub 2009 Dec 2.
In this article, hollow gold nanospheres (HGN) were prepared by using Co nanoparticles as sacrificial templates and varying the stoichiometric ratio of HAuCl(4) over the reductants. The HGN was then modified on the electrode surface via a 1,6-hexanedithiol linking agent to fabricate a novel electrochemical DNA biosensor. The whole DNA biosensor fabrication process was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods with the use of ferricyanide as an electrochemical redox indicator. The probe DNA immobilization and hybridization on the modified electrode was further studied with CV and differential pulse voltammetry (DPV) methods by using Co(phen)(3)(3+) as an electrochemical hybridization indicator. Results revealed that the HGN modified electrode, especially for the HGN with the outer surface surrounded by densely spike-like nanocrystallites, could largely enhance the DNA hybridization ability. The fabricated DNA biosensor was proved to have a low detection limit (1 pM) and a wide dynamic range (from 1 pM to 10nM) with a high stability and reusability.
本文采用 Co 纳米粒子作为牺牲模板，通过改变 HAuCl4 与还原剂的化学计量比来制备空心金纳米球（HGN）。然后，通过 1,6-己二硫醇连接剂将 HGN 修饰在电极表面上，以构建新型电化学 DNA 生物传感器。使用铁氰化钾作为电化学氧化还原指示剂，通过循环伏安法（CV）和电化学阻抗谱（EIS）方法对整个 DNA 生物传感器的制备过程进行了表征。通过 CV 和差分脉冲伏安法（DPV）方法，进一步使用 Co(phen)(3)(3+)作为电化学杂交指示剂研究了修饰电极上探针 DNA 的固定和杂交。结果表明，HGN 修饰电极，特别是表面周围密集地覆盖着刺状纳米晶的 HGN，能够大大提高 DNA 的杂交能力。所构建的 DNA 生物传感器具有低检测限（1 pM）和宽动态范围（从 1 pM 到 10nM），具有高稳定性和可重复性。
