Label-free impedimetric thrombin sensor based on poly(pyrrole-nitrilotriacetic acid)-aptamer film

A label-free and highly sensitive impedimetric aptasensor was developed based on electropolymerized film for the determination of thrombin. The first step is the electrogeneration of a poly(pyrrole-nitrilotriacetic acid) (poly(pyrrole-NTA)) film onto the surface of electrodes followed by complexation of Cu2+ ions. Then, the histidine labeled thrombin aptamer was immobilized onto the electrode through coordination of the histidine groups on the NTA–Cu2+ complex. The aptamer sensor was applied for the detection and quantification of thrombin via impedimetric detection without a labeling step. A linear quantification of thrombin was obtained in the range 4.7×10–12–5.0×10−10 mol L−1 with a sensitivity of 2838 Ω/log unit (R2=0.9984). The impedance modulus at 0.3 Hz as a function of thrombin concentration was used to elaborate a similar linear relationship from 4.7×10–12 to 5×10−10 mol L−1. In addition, aptamer-poly(pyrrole-NTA) electrodes incubated for 40 min in aqueous solutions of bovine serum albumin (BSA), lysozyme and IgG (5×10−7 mol L−1) did not exhibit non-specific adsorption of proteins. Moreover, it has been demonstrated that the selective sensor can be regenerated several times with a good reproducibility.

Références

Titre
Label-free impedimetric thrombin sensor based on poly(pyrrole-nitrilotriacetic acid)-aptamer film
Type de publication
Article de revue
Année de publication
2013
Revue
Biosensors and Bioelectronics
Volume
41
Pagination
90 - 95
ISSN
0956-5663
Soumis le 18 mai 2018