Cystic fibrosis: a label-free detection approach based on thermally modulated electrochemical impedance spectroscopy
2010 (English)In: Analytical and Bioanalytical Chemistry, ISSN 1618-2642, E-ISSN 1618-2650, Vol. 396, no 7, 2565-2574 p.Article in journal (Refereed) Published
Cystic fibrosis is one of the most commongenetically inherited diseases in northern Europe, with theDF508 mutation being the most common, and among theCaucasian population being responsible for almost 70% ofcases. In this work, we report on the use of thermallymodulated electrochemical impedance spectroscopy for thediscrimination of the DF508 mutation from the wild-typesequence. DNA probes (15 and 21 bases long) wereimmobilised on the surface of gold electrodes and thevariation of the charge-transfer resistance was monitored asa function of hybridisation. Two sets of targets were used inthis work: synthetic 15-mer sequences and two singlestrandedsynthetic analogues of PCR products 82 (mutant)and 85 (wild type) bases long. Hybridisation with shorttargets resulted in very sequence specific charge-transferresistancevariation with a discrimination factor at roomtemperature between fully complementary and mismatchedsequences of approximately fivefold. However, in the caseof the single-stranded synthetic PCR product analogues, alower discrimination factor was recorded (1.5-fold). Theeffect of temperature was investigated to improve discriminationand the use of a posthybridisation wash at elevatedtemperature resulted in a fivefold improvement in thediscrimination factor. Using an electrode array with probesimmobilised against each of the mutant and wild-typesequences, we achieved an unequivocal detection of theDF508 mutation.
Place, publisher, year, edition, pages
Springer Publishing Company, 2010. Vol. 396, no 7, 2565-2574 p.
Electrochemical impedance spectroscopy . Cystic fibrosis . Label-less detection .DNA sensor . DF508
IdentifiersURN: urn:nbn:se:liu:diva-92112DOI: 10.1007/s00216-010-3489-yPubMedID: 20155413OAI: oai:DiVA.org:liu-92112DiVA: diva2:620161