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Comparison of DNA Hybridization at Rotating and Heated Gold Disk Electrodes
Author(s) -
Peter Jörg,
Reske Thomas,
Flechsig GerdUwe
Publication year - 2007
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200703881
Subject(s) - osmium tetroxide , electrode , rotating disk electrode , osmium , analytical chemistry (journal) , chemistry , voltammetry , square wave , monolayer , oligonucleotide , cyclic voltammetry , materials science , electrochemistry , ruthenium , dna , chromatography , organic chemistry , catalysis , biochemistry , physics , electron microscope , voltage , quantum mechanics , optics
This paper reports about the influence of temperature, hybridization time and convection upon the detection of osmium tetroxide bipyridine‐labeled target oligonucleotides at rotating gold disk (RDE) and heated low temperature co‐fired ceramics (LTCC) gold disk electrodes. We used mixed self‐assembled monolayers of hexathiol‐linked probe oligonucleotides and mercaptohexanol on the gold surface of the electrodes for the hybridization detection of the labeled targets by means of square‐wave voltammetry. Due to protective strands, the osmium tetroxide‐modified target strands were still able to hybridize with the immobilized probe strands. The hybridization of such osmium tetroxide bipyridine‐modified target strands with thiol‐linked probe strands immobilized on gold yielded large reversible square‐wave‐voltammetric signals. Rotation speed and, hence, mass transport due to convection has only marginal effects. On the other hand, temperature affects greatly the hybridization step as indicated by both heated LTCC electrode in cold and RDE in warm hybridization solution. Calculated detection limits of 3.6 and 3.1 nM targets at the RDE and the LTCC electrode, respectively, have been almost the same at both types of electrodes. Applying an appropriate temperature during hybridization is more important than mechanically enhanced mass transport.