title: Electrochemical detection of individual DNA hybridization events.
abstract: We report on real-time electrochemical detection of individual DNA hybridization events at an electrode surface. The experiment is carried out in a microelectrochemical device configured with a working electrode modified with single-stranded DNA probe molecules. When a complementary DNA strand labelled with a catalyst hybridizes to the probe, an easily detectable electrocatalytic current is observed. In the experiments reported here, the catalyst is a platinum nanoparticle and the current arises from electrocatalytic oxidation of hydrazine. Two types of current transients are observed: short bursts and longer-lived steps. At low concentrations of hydrazine, the average size of the current transients is proportional to the amount of hydrazine present, but at higher concentrations the hydrazine oxidation reaction interferes with hybridization.
authors.affiliation: Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, TX 78712-0165, USA.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Alligrant
authors.forename: Elizabeth G
authors.initials: EG
authors.lastname: Nettleton
authors.forename: Richard M
authors.initials: RM
authors.lastname: Crooks
mesh_terms: D015374:Biosensing Techniques; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D004277:DNA, Single-Stranded / Q000737:chemistry; D004563:Electrochemistry / Q000379:methods*; D004566:Electrodes; D006834:Hydrazines / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry; D009693:Nucleic Acid Hybridization; D010084:Oxidation-Reduction; D010984:Platinum / Q000737:chemistry; D017422:Sequence Analysis, DNA
chemical_list: D004277:DNA, Single-Stranded; D006834:Hydrazines; C029424:hydrazine; D010984:Platinum