G-Quadruplex-Based DNAzymes Aptasensor for the Amplified Electrochemical Detection of Thrombin

A novel G-quadruplex-based DNAzymes aptasensor for the amplified electrochemical detection of thrombin has been described. The aptasensor utilized a combination of hemin and guanine-rich thrombin-binding aptamer (TBA) to form horseradish peroxidase (HRP)-mimicking DNAzymes with peroxidase catalytic activity. In the presence of thrombin, the enzyme activity could be extensively promoted, thereby providing the amplified electrochemical read-out signals for detecting thrombin. This aptasensor exhibited high sensitivity and selectivity for thrombin determination, which enabled the analysis of thrombin with a detection limit of 6 x 10(-11) M. On the basis of results, this method could have broad applications in the detection of proteins and other biomolecules.