Electron Transfer throughThiol-modified Sticky End Oligonucleotides

Abstract

Electron flow through DNA films provides an excellent means for mutation detection. Recently, thiol-terminated DNA monolayers deposited on gold electrodes have been used to detect mismatches by solution electrochemistry. In this method, single stranded thiolated DNA has been linked to a gold electrode and then hybridized with a complementary test strand to form duplexes. The DNA-coated electrode was then exposed to an intercalator and a potential difference was applied to push charge through the DNA. Duplexes with single base pair mismatches showed minimal charge flow while charge flow through wild type, matched, duplexes was uninhibited. Our research focuses on developing a more efficient and elegant apparatus for such mutation detection. Presently, each film may be used for only one test. However, through our research, we hope to develop a method which would allow for multiple tests using a single film. In this procedure, thiol-terminated DNA duplexes with a 'sticky end' are linked to a gold electrode. Test duplexes with a complementary 'sticky end' can then be hybridized to the monolayer for mutation detection and then de-hybridized after experimentation. Other duplexes can then be hybridized to the same film for further detection.