Electrochemical genosensing by using hybridization indicator

This approach is based on the electrochemical response of a redox active label changes upon DNA hybridization, when the hybridization process occurs due to change of the indicator concentration at the electrode surface [38]. These redox active labels can be called as hybridization indicators and have high affinity for either ssDNA or dsDNA to transduce hybridization. 

Hybridization indicators have various interaction properties of dsDNA and ssDNA. Some metal complexes or dyes are intercalator molecules which interact with hydrogen bonds of dsDNA [39], and some indicators have selective binding processes onto DNA bases such as guanine [40]. 

Intercalator hybridization labels are complex molecules that have a planar aromatic group. Several methods for indicator-based electrochemical sequence specific to DNA detection have been reported. Wang et al. [41] described the hybridization detection of short DNA sequences related to HIV virus genome due to the chronopotentiometric transduction of Co(phen) as an hybridization label. Electrochemiluminescense assays have also been reported by Carter etal. [42] for specific DNA sequence detection. 

Early studies on electrochemical nucleic acid biosensors were based on electrochemical transduction of redox labels (indicators) that have significant different behaviors between dsDNA and ssDNA. These intercalator molecules have higher binding affinity to dsDNA than ssDNA. Mikkelsen and coworkers investigated this approach by using Co(phen) as a hybridization indicator. The intercalator molecule was accumulated at ss and dsDNA at covalently attached 

Our group is also focused on the detection of clinical analysis based on intercalator molecules and on voltammetric transduction 

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