Catalytic Amplification of Electrochemical Signal in Homogeneous Solution Using an Entropy-driven DNA Circuit.

The electrochemical signal from ferrocene on a DNA probe was successfully modulated in a homogeneous solution by the template-directed formation and dissociation of an inclusion complex with ß-cyclodextrin on another probe. The electrochemical response was amplified by combining with a DNA circuit, in which the target DNA served as a catalyst. This system did not require any modification of a complementary DNA with the ferrocene-modified probe on the electrode surface to separate the bound/free probe for the detection of 200 nM target DNA.