Indicator based and indicator-free electrochemical DNA biosensors

Nucleic acids have become the ultimate tools in the recognition and monitoring of many important compounds. There is a great demand for a detection system which cannot only determine specific DNA fragments, but can also determine the exact total nucleic acid content of a sample. For more than a decade, DNA biosensor technologies are under intense investigation owing to their great promise for rapid and low-cost detection of specific DNA sequences in human, viral and bacterial nucleic acids. Here we describe an electrochemical DNA biosensor for the detection of DNA hybridization using the oxidation signals of guanine and adenine and the reduction signals of MB in connection with DPV.