Electrochemical DNA Hybridization Sensor Using Poly[vinylpyridine Os(bipyridine)2Cl]-co-Ethylamine Redox Polymer

DNA hybridization sensors are important for diseases diagnosis. Until now, many approaches have been proposed for the DNA hybridization examination. These include fluorescence based, electrochemical and colorimetric based. Electrochemical hybridization for detection of DNA sequences requires the development of easy to-use, fast, inexpensive, miniaturized analytical devices. In this work, a simple electrochemical DNA hybridization sensor that uses poly[vinylpyridine Os(bipyridine)2Cl]-co-ethylamine redox polymer as the indicator was assembled. The electrochemical behavior of poly[vinylpyridine Os(bipyridine)2Cl]-co-ethylamine redox polymer polymer with both single stranded DNA (ssDNA-SH) probe and double stranded DNA (dsDNA) was determined. Both cyclic voltammetry and impedance spectroscopy results indicated strong binding of the new redox polymer onto DNA. A hybridization process involving a monolayer of a 24-mer thiol-tethered DNA capture probe on gold electrode and the corresponding complementary strand were clearly demonstrated. DNA double strand after disruption with free radicals could also be detected. The biosensor system has potential for use to recognize of damaged DNA sequences.