Authors: H. Zhou, K-S Ma, J. Zoval and M. Madou
Affilation: University of California, Irvine, United States
Pages: 481 - 484
Keywords: electrical detection, DNA hybridization, Adjacent Impedance Probing (AIP)
Sensitivity and selectivity are two of the most challenging criteria for the development of DNA biosensor devices. These biosensor devices have attracted interest for the rapid identification of pathogens in humans, animals, and plants, for the detection of specific genes in animal and plant breeding and in the diagnosis of human genetic disorders. Traditionally, molecular diagnostic detection has relied on fluorescent or radioactive labels, and signal transduction is performed with equipment that greatly increases size and cost of the whole system. Electronic detection is expected to involve less complicated and smaller instrumentation while detection limits are maintained. Previous efforts on impedance-based DNA biosensors show limitations on repeatability, sensitivity and selectivity. In this work, we introduce the Adjacent Impedance Probing (AIP) technique for DNA hybridization detection. In this novel method, the DNA hybridization site is employed for the bio-recognition event (this site does not necessarily need an underlying conductor surface) and a bare adjacent conductor electrode is employed for generating the largest possible impedance change through the deposition of an insulating material or through chemical passivation induced by the enzymatic reporter reaction.