A dual-mode electrochemical aptasensor for the detection of Mucin-1 based on AuNPs-magnetic graphene composite

Herein, a dual-mode electrochemical aptasensor was proposed for the detection of Mucin-1 (MUC1). AuNPs-Magnetic graphene composite (AuNPs-MG), synthesized through hydrothermal reaction and a subsequent reduction of chloroauric acid in situ, exhibited the ability to absorb methylene blue (MB) by pi-pi interaction and behavior similar to peroxidase. Moreover, the presence of AuNPs provided the possibility to covalently bond to thiolated DNA. Two electrochemical labels based on the AuNPs-MG were prepared based on this characteristic. In the strand displacement-based electrochemical aptasensor, complementary DNA (CP) in CP-aptamer double-strand DNA exposed owing to the higher affinity between aptamer and MUC1 could capture the electrochemical label through the complementary base pairing principle. Under the optimal conditions, the aptasensor was applied to detect a series concentration of MUC1 by square wave voltammetry (SWV) and chronoampemmetry (CA), respectively. The aptasensor shows satisfactory detection results with wide linear ranges of 10 fM to 10 nM through SWV mode and 100fM to 100 nM through CA mode. Meanwhile, the proposed aptasensor with good reproducibility, stability, and possibility in detecting artificial serum samples were obtained, indicating the great potential in clinical analysis applications.

Automated summary

A dual-mode electrochemical aptasensor for the detection of MUC1 was proposed. AuNPs-MG composite was synthesized and exhibited the ability to absorb methylene blue and behave like a peroxidase. The aptasensor showed satisfactory detection results with wide linear ranges and exhibited good reproducibility, stability, and the potential for clinical analysis applications.