An electrochemical aptasensor based on hybridization chain reaction with enzyme-signal amplification for interferon-gamma detection
- 作者：Jingjin Zhao ; Chunfei Chen ; Liangliang Zhang ; Jianhui Jiang ; Ruqin Yu ; rqyu@hnu.edu.cn
- 关键词：Interferon-gamma ; Aptamer ; Electrochemical sensor ; Hybridization chain reaction
- 刊名：Biosensors and Bioelectronics
- 出版年：2012
- 期刊代码：12_09565663
- 类别：ch
- 出版时间：June-July, 2012
- 卷：36
- 期：1
- 页码：129-134
- 文件大小：665 K
摘要
A novel electrochemical aptasensor based on hybridization chain reaction (HCR) with enzyme-signal amplification was constructed for the detection of interferon-gamma (IFN-纬). In this aptasensor, the recognition probes which contained the sequence of IFN-纬 aptamer were initially binded to IFN-纬, and the unbound recognition probes were captured on the electrode as an initiator to trigger the HCR. The two DNA hairpins bio-H1 and bio-H2 were opened by the recognition probe, and bound one by one on the electrode. The biotin was used as a tracer in the hairpins and streptavidin-alkaline phosphatase (SA-ALP) as a reporter molecule. Then, SA-ALP converted its electro-inactive substrate 1-naphthyl phosphate into an electroactive derivative 1-naphthol generating amplified electrochemical signal by differential pulse voltammetry (DPV). The activity of the immobilized enzyme was voltammetrically determined by measuring the amount of 1-naphthol generated for enzymatic dephosphorylation of 1-naphthyl phosphate. The electrochemical signal observed was inversely related to the concentration of IFN-纬. The proposed approach showed a high sensitivity for IFN-纬 in a concentration range of 0.5-300 nM with a detection limit of 0.3 nM. The sensing system also provided satisfactory results for the detection of IFN-纬 in the cell media.