Abstract: The hybridization of oligonucleotide probe with matched or mismatched DNA target was monitored by a combination of electrochemical control and in situ quartz crystal microbalance technique. The results indicated that the apparent efficiency of hybridization for matched DNA target at a positive potential was higher than that at a negative potential. But an obvious response of “false positives”may be obtained at the positive potential. Application of negative potential can availably halt hybridization for mismatched target DNA. The effect of the orientation of oligonucleotide probe and micro forces on DNA hybridization under interface electric field was discussed.

Key words: Electrochemical quartz crystal microbalance( EQCM), DNA hybridization, Interface electric field, False positives