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Effects of Ionic Strength and Probe DNA Length on the Electrochemical Impedance Spectroscopic Response of Biosensors
Author(s) -
RevengaParra Mónica,
García Tania,
Pariente Félix,
Lorenzo Encarnación,
Alonso Concepción
Publication year - 2011
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.201000365
Subject(s) - dielectric spectroscopy , biosensor , oligonucleotide , dna , ionic strength , electrochemistry , ionic bonding , transduction (biophysics) , duplex (building) , analytical chemistry (journal) , materials science , dna–dna hybridization , biophysics , chemistry , electrical impedance , electrode , nanotechnology , biology , biochemistry , ion , chromatography , physics , organic chemistry , quantum mechanics , aqueous solution
Impedance spectroscopy (EIS) has been proposed as the transduction principle for detecting the hybridization of DNA complementary strands. The resistance offered to the electrochemical reaction acts as the working signal, allowing an unlabelled gene assay. In our experiments, atypically large DNA oligonucleotides (110 base pairs) were used to determine the influence of ionic strength on the response of the DNA biosensor. In addition, the EIS response that was obtained by the hybridization process in the presence or absence of 6‐mercapto‐1‐hexanol (MCH) was also evaluated. Finally, we extended these studies to probes and duplexes of various lengths observing a linear relationship between duplex length and the response (expressed as the R CT value).