title: Electrocatalytic activity of DNA on electrodes as an indication of hybridisation.
abstract: Electron transfer between metal electrodes and ferro/ferricyanide is completely suppressed at low ionic concentration. We describe here a new phenomenon related to this reaction: an immobilisation of thiolated single-stranded DNA on gold electrodes retains this activity at low ionic strength up to the level corresponding to the high ionic strength. In contrast, a hybridisation of the complementary DNA with the thiolated single-stranded DNA followed by a binding onto the electrodes, attenuated the electrocatalytic effect. These effects can be used for discrimination between single-stranded DNA and double-stranded DNA and for semi-quantitative measurement of complementary DNA in a sample.
authors.affiliation: Institute of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, D-93040 Regensburg, Germany.
authors.forename: Zheng-liang
authors.initials: ZL
authors.lastname: Zhi
authors.forename: Viktor
authors.initials: V
authors.lastname: Drazan
authors.forename: Otto S
authors.initials: OS
authors.lastname: Wolfbeis
authors.forename: Vladimir M
authors.initials: VM
authors.lastname: Mirsky
mesh_terms: D020029:Base Pairing; D002384:Catalysis; D004247:DNA / Q000737:chemistry* / Q000235:genetics; D004563:Electrochemistry; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D009693:Nucleic Acid Hybridization; D013057:Spectrum Analysis
chemical_list: D006046:Gold; D004247:DNA