Sensor array: Impedimetric label-free sensing of DNA hybridization in real time for rapid, PCR-based detection of microorganisms

A novel, impedance-based electronic sensor format was used for label-free, real-time detection of microbial DNA on oligonucleotide probe arrays. Detection limits of 5 - 10 nM were achieved for single-stranded, PCR-amplified DNA targets. Hybridization selectivity yielded 9- to 12-fold signal increases for specific targets, and the sensor arrays were re-used multiple times without significant signal degradation. These and other features of the SHARP Laboratories of America (SLA) sensor array, such as its ability to acquire continuous measurements of DNA as it accumulates on the array surface, make it an attractive biosensor platform for field detection and monitoring of sentinel and/or pathogenic microorganisms.