A homogeneous electrochemical aptasensor based on signal amplification mode of host-guest recognition between bisferrocene and β-CD for sensitive detection of thrombin

In this study, bisferrocene was synthesized, and modified on both terminals of thrombin aptamer (TBA) as electrochemical signal marker. Subsequently, an electrochemical homogeneous aptasensor for the sensitive and rapid detection of thrombin was constructed by a signal amplification mode of host-guest recognition between bisferrocene and β-cyclodextrin (β-CD). After binding of thrombin, TBA changed from the original stem-loop structure to G-quadruplex, and the bisferrocene entered the cavity of β-CD modified on the surface of the gold electrode through the host-guest recognition, generating a stable electrochemical current signal. This signal amplification strategy revealed a dynamic range from 20 pmol/L to 62. 5 nmol/L with a detection limit of 8. 4 pmol/L. This aptasensor shows high specificity and satisfactory stability for thrombin, and provides a feasible solution for the rapid detection of thrombin. © 2021, Youke Publishing Co.,Ltd. All rights reserved.