The electrochemical DNA biosensor

Sequence-specific detection of either genetically or pathogenically associated nucleic acids has become increasingly important for applications including point-of-care diagnostics, antiterrorism; environmental monitoring and forensic analysis. Therefore, it is highly desirable to develop DNA detection methods with high sensitivity and selectivity, as well as speed, which has motivated the development of various optical, electronic and acoustic DNA biosensors. Because electrochemical detectors are inexpensive, portable and power-saving, electrochemical DNA biosensors have been widely recognized to be a highly promising approach to detect clinical, environmental and security relevant nucleic acids, especially when time, money or resources are limited. The development of the research on electrochemical DNA biosensor, one of the most important branch of DNA biosensors, is reviewed. A typical electrochemical DNA sensor involves an electrode and surface-confined capture probe DNA. Upon hybridization of the immobilized probes to the sequence-specific target DNA, redox labels that either intercalatively bind to the hybridized double-stranded DNA or covalently tagged to DNA strands generate corresponding electrochemical signals. The immobilization of DNA probes and electrochemical transduction of DNA hybridization. are summarized.