ABSTRACT
The development of microelectronic chip or array devices has overcome many of the limitations of passive hybridization techniques. These active electronic array devices facilitate: (1) the ability to produce reconfigurable electric fields on the microarray surface that allows the rapid and controlled transport of charged molecules to any test site; (2) the ability to carry out site selective DNA probe/target addressing and hybridization; (3) the ability to greatly increase DNA hybridization rate by concentration of probe/target DNA at the test site; and (4) the ability to use electronic stringency to improve hybridization specificity for point mutation, SNP, and STR analysis. In addition to DNA and RNA molecules, these devices have the ability to selectively transport any charged entity, which can include proteins (antibodies, enzymes, etc.), cells, nanoparticles, and semiconductor microstructures. These chips or arrays are microelectronic devices that exploit both microfabrication and microelectronic technology. More importantly, they are referred to as ‘‘active’’ electronic devices because they use electric fields-in particular, electrophoretic fields-to selectively transport DNA or other molecules and to directly affect the hybridization reactions or other affinity reactions occurring on the surface of the array [9-12].
