Electric-field-pulse-assisted covalent immobilization of DNA in the nanosecond time scale

A single square voltage pulse is used to achieve the selective covalent bonding of DNA probes to a functionalized thin-film surface $({\mathrm{SiO}}_2)$ on a plastic substrate. Significant covalent bonding occurs with only 100 ns of pulse duration, representing a decrease in immobilization time of more than ten orders of magnitude from the 2 h needed without electric field. A systematic study of the effect of the duration and rise/fall times of the voltage pulse on the immobilization of DNA probe molecules is presented. Successful hybridization of the DNA probes immobilized using this technique with a complementary target strand was achieved.