Electrochemical Interrogation of Interactions between Surface-Confined DNA and Methylene Blue

In this work, we reported a systematic investigation on the interactions betweenmethylene blue (MB) and surface-confined DNA by using electrochemical methods. Wedemonstrated that the redox potential of MB and binding and dissociation kinetics of MB toDNA differed significantly for single-stranded DNA (ss-DNA) and double-stranded DNA(ds-DNA) immobilized on gold electrodes. This was possibly due to the different bindingmechanism between MB and ss- or ds-DNA. This work might provide useful informationfor developing MB-based sequence-specific electrochemical DNA sensors.