Electric-field Assisted Immobilization and Hybridization of DNA Oligomers on Microcantilever Sensors

Gold-coated microcantilevers were used to develop sensitive micromechanical biosensor for detecting mismatch mutations in DNA hybrids. The selective 5'-end immobilization of 25-mer single-stranded (ss) DNA probes to a gold-coated cantilever surface and the specific hybridization of ssDNA targets to the immobilized probe were performed by the direct electric field control. The controlled electric fields were used to regulate the transport of charged oligo-nucleotides. More than 70% of the immobilization and hybridization can be carried out in 2-3 seconds, and the detection rates are at least 102 times faster than in the passive control reactions performed without electric field