title: Immobilization and hybridization by single sub-millisecond electric field pulses, for pixel-addressed DNA microarrays.
abstract: Single square voltage pulses applied to buried electrodes result in dramatic rate increases for (1) selective covalent bonding (immobilization) of single-stranded DNA (ssDNA) probes to a functionalized thin film SiO(2) surface on a plastic substrate and (2) hybridization of ssDNA to the immobilized probe. DNA immobilization and hybridization times are 100 ns and 10 micros, respectively, about 10(9) times faster than the corresponding passive reactions without electric field. Surface coverage is comparable. Duration, magnitude and slew rate of the voltage pulse are all key factors controlling the rates of ssDNA immobilization and hybridization. With rise times of 4.5 ns, pulses shorter than 1 ms and voltages below 1V are effective. The ssDNA adsorbed on the surface is reoriented by the rapidly changing electric field. This reduces steric barriers and speeds the immobilization and hybridization reactions. These results open the way for pixel-addressed microarrays driven by silicon microelectronics circuits.
authors.affiliation: INESC Microsistemas e Nanotecnologias (INESC-MN), Rua Alves Redol, 9, 1000-029 Lisbon, Portugal. ffixe@inesc-mn.pt
authors.forename: F
authors.initials: F
authors.lastname: Fixe
authors.forename: H M
authors.initials: HM
authors.lastname: Branz
authors.forename: N
authors.initials: N
authors.lastname: Louro
authors.forename: V
authors.initials: V
authors.lastname: Chu
authors.forename: D M F
authors.initials: DM
authors.lastname: Prazeres
authors.forename: J P
authors.initials: JP
authors.lastname: Conde
mesh_terms: D000327:Adsorption / Q000528:radiation effects; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D004247:DNA / Q000737:chemistry* / Q000528:radiation effects*; D015342:DNA Probes / Q000737:chemistry* / Q000528:radiation effects*; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D004574:Electromagnetic Fields; D004867:Equipment Design; D019544:Equipment Failure Analysis; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation* / Q000379:methods
chemical_list: D015342:DNA Probes; D004247:DNA