Label-free electrochemical impedance peptide-based biosensor for the detection of cardiac troponin Ⅰ incorporating gold nanoparticles modified carbon electrode
A label-free electrochemical impedance spectroscopy (EIS) biosensor for highly sensitive detection of cardiac troponin Ⅰ (TnⅠ) as a model target was developed by employing gold nanoparticle (GNPs) modified glassy carbon electrode (GCE) as a base electrode.A special peptide (CFYSHSFHENWPS) was used as molecular recognition probe.GNPs were firstly electrochemically deposited onto the surface of GCE and polyethylene glycol was then used to block any remaining sites of the surface of GCE.The biosensor was fabricated by thiol self-assembling the peptide probe onto the surface of gold nanoparticles and finally blocking any remaining sites of the surface of GNPs using 6-mercapto-1-hexanol.A suitable equivalent electrical circuit consisting of parallel double Randles circuit with phase angle elements greatly fits the experiment electrochemical cell.Upon the binding of TnⅠ,the charge transfer resistance (Rct) of the biosensor was logarithmically direct proportional to the concentration of TnⅠ in the range from 15.5 pg/mL to 1.55 ng/mL with a detection limit of 3.4 pg/mL.It was found that GNPsmodified GCE as a platform for the immobilization of the peptide can greatly reduce the background EIS signal and enhance the EIS response to the target.This biosensor has been used for assay of real serum sample with satisfactory results.Thiswork demonstrates that GNPs modified GCE for the immobilization of molecular recognition element is promising platform for the development of label-free electrochemical biosensors for the determination of special proteins.
Biosensor Electrochemical impedance spectroscopy Gold nanoparticles Cardiac troponin Ⅰ Peptide
Bing Wang Rui Jing Honglan Qi Qiang Gao Chengxiao Zhang
Key Laboratory of Analytical Chemistry for Life Science of Shaanxi Province,School of Chemistry and Chemical Engineering,Shaanxi Normal University,Xian 710062,PR China
国际会议
南京
英文
212-217
2016-12-23（万方平台首次上网日期，不代表论文的发表时间）