A homogeneous strategy of target-triggered catalytic hairpin assembly for thrombin signal amplification

摘要

Sensitive and rapid detection of thrombin is play an important role in biomedical and biological analysis. In this work, tetraferrocene was synthesized and used for the construction of a homogeneous electrochemical aptasensor for sensitive and rapid detection of thrombin in human serum via coupling host-guest recognition of tetraferrocene and beta-CD with catalytic hairpin assembly (CHA) signal amplification. The presence of target thrombin causes unfoldment of a large number of double hairpin probes (H1). Subsequently, two tetraferrocenes modified on H1 enter the beta-CD's cavity modified on a gold electrode (AuE) based on host-guest recognition of tetraferrocene and beta-CD, which drastically amplifies the current response for thrombin detection. The prepared aptasensor shows a wide linear relationship between 1 pM and 3.125 nM, and detection limit of 0.28 pM. More importantly, this homogeneous strategy provides essential information for the manufacturing of sensors for sensitive and rapid analysis of other biomarkers.