Electrochemical aptasensor based on conductive supramolecular polymer hydrogels for thrombin detection with high selectivity

Abstract

Herein, we synthesized a kind of conductive supramolecular polymer hydrogel (CSPH) based on polyaniline (PANI) which can not only improve the conductivity but also promote antifouling performance of the aptasensor for the specific recruitment of thrombin (TB) from complex samples. With the electrochemical copolymerization of aniline (AN) and 3-aminophenylboronic acid (ABA) on glassy carbon electrode (GCE), the electrode was then inserted into the polyvinyl alcohol (PVA) solution to obtain robust CSPH through boric acid groups incorporated onto PANI to cause gelation of PVA solution, owing to the hydrophilicity of CSPH and nearly electrical neutrality, the modified electrode is antifouling without integration of other antifouling materials. A sandwich-type electrochemical aptasensor was constructed on the CSPH based electrode interfaces. Thrombin aptamer 1 (TBA1) were modified on the CSPH through amide bond, and thrombin aptamer 2 modified magnetic nanoparticles (MNP-TBA2) are used as signal amplification probes, the aptasensor has good sensitivity with a linear range from 1 pmol/L to 10 nmol/L and has a detection limit down to 0.64 pmol/L. The strategy of utilizing eletropolymerization of CSPH films to undergo highly selective thrombin recognition is, of course, readily extended to a broad range of targets in the real samples, and the recovery was ranging from 95.2% to 106.3% and RSDs varying from 2.3% to 4.5%.