Ultrasensitive and Specific Electronic Transduction of DNA Sensing Processes

Amplified electronic transduction of DNA sensing is accomplished by the application of a biocatalytic probe that precipitates an insoluble product on the transducer as a result of the DNA sensing. Alternative amplification of DNA sensing is achieved by the use of functionalized liposomes that bind to the electrode upon the sensing process. Single base mutations in DNA are detected by the polymerase-induced coupling of a biotinylated base complementary to the mismatch site, followed by the biocatalyzed precipitation of an insoluble product on the transducer. DNA biosensors of unprecedented sensitivity and specificity are designed. Faradaic impedance spectroscopy and microgravimetric quartz-crystal-microbalance measurements are used for the electronic transduction of the DNA sensing.