期刊
BIOSENSORS & BIOELECTRONICS
卷 64, 期 -, 页码 611-617出版社
ELSEVIER ADVANCED TECHNOLOGY
DOI: 10.1016/j.bios.2014.09.072
关键词
Photoelectrochemical; Thrombin; Aptamer; Graphene-CdS; Hexaammineruthenium(III) chloride
类别
资金
- National Basic Research Program of China [2010CB732400]
- Key Program from the National Natural Science Foundation of China [21035002]
- National Natural Science Foundation of China [21375014, 21175021]
- Social Development Project of Jiangsu [BE2012731]
- Social Development Project of Suzhou [ZXY2012027]
A photoelectrochemical (PEC) aptasensor for highly sensitive and specific detection of thrombin was developed by using graphene-CdS nanocomposites multilayer as photoactive species and electroactive mediator hexaammineruthenium(III) chloride (Ru(NH3)(6)(3+)) as signal enhancer. Graphene-CdS nanocomposites (G-CdS) were synthesized by one-pot reduction of oxide graphene and CdCl2 with thioacetamide. The photoactive multilayer was prepared by alternative assembly of the negatively charged 3-mercaptopropionic acid modified graphene-CdS nanocomposites (MPA-G-CdS) and the positively charged polyethylenimine (PEI) on ITO electrode. This layer-by-layer assembly method enhanced the stability and homogeneity of the photocurrent readout of G-CdS. Thrombin aptamer was covalently bound to the multilayer by using glutaraldehyde as cross-linking. Electroactive mediator Ru(NH3)(6)(3+) could interact with the DNA phosphate backbone and thus facilitated the electron transfer between G-CdS multilayer and electrode and enhanced the photocurrent. Hybridizing of a long complementary DNA with thrombin aptamer could increase the adsorption amount of Ru(NH3)(6)(3+), which in turn boosted the signal readout. In the presence of target thrombin, the affinity interaction between thrombin and its aptamer resulted in the long complementary DNA releasing from the G-CdS multilayer and decreasing of photocurrent signal. On the basis of G-CdS multilayer as the photoactive species, Ru(NH3)(6)(3+) as an electroactive mediator, and aptamer as a recognition module, a high sensitive PEC aptasensor for thrombin detection was proposed. The thrombin aptasensor displayed a linear range from 2.0 pM to 600.0 pM and a detection limit of 1.0 pM. The present strategy provided a promising ideology for the future development of PEC biosensor. (C) 2014 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据