Electrochemical Detection of DNA Melting Curves by Means of Heated Biosensors

This article reports about the detection of DNA melting curves at heated electrochemical biosensors. Osmium tetroxide-bipyridine-labeled target oligonucleotides are hybridized with probe oligonucleotides immobilized on gold electrodes. Then, the gold electrode is successively heated in order to measure a complete melting curve consisting of alternating current voltammetric signals. Melting temperatures theta(m), determined at various ionic strengths an in dependence on different numbers of base pair mismatches, have been compared with those obtained by means of UV spectrophotometry. The proposed method holds great promise for the fast and easy parallel detection of nucleic acids sequences on selectively heated electrode arrays. A stringent hybridization temperature can be easily adjusted in order to discriminate base pari mismatches.