A sensitive and label-free electrochemical impedance biosensor for protein detection based on terminal protection of small molecule-linked DNA

作者：Wang, Hai-Bo^*; Zhang, Hong-Ding; Xu, Shu-Ping; Gan, Tian; Huang, Ke-Jing; Liu, Yan-Ming

来源：Sensors and Actuators B: Chemical , 2014, 194: 478-483.

DOI：10.1016/j.snb.2014.01.002

• Electrochemical impedance
• Label free biosensor
• Small molecule-linked DNA
• Terminal protection

In this paper, a label-free electrochemical impedance biosensor has been developed for protein detection based on terminal protection of small molecule linked-DNA. This strategy was demonstrated using folate (FA) and its binding protein folate receptor (FR) as a model case. In the present terminal protection system, with the increase of FR, it could protect more FA linked-DNA from hydrolysis by exonuclease I (Exo I), resulting in an increased electron transfer resistance response. By taking the advantage of the terminal protection assay, this label-free electrochemical biosensor achieved highly sensitive and selective detection of FR with a detection limit of 3 pM and a linear range from 10 pM to 500 nM, which was lower than some previously reported methods. Moreover, the label-free method did not need specific labelling and showed sequence-independent with DNA probes. Thus, it may offer a simple, cost-effective, highly selective and sensitive platform for electrochemical impedance detection of small molecule-protein interactions in clinical diagnostics.

• 出版日期2014-4
• 单位信阳师范学院