Electrochemistry of DNA-bound redox probes using Alkyne-terminated oligonucleotides "clicked" to Azide-terminated Thiols on gold electrodes

Abstract

Using modern electrochemical techniques, DNA has been shown to conduct electricity like a wire by mediating charge through its stack of pi-orbitals. Using the ?Click Reaction? developed by Rolf Huisgen in the 1960s to effectively and efficiently attach azides to terminal alkynes, this summer we have shown that is possible to ?click? a small alkyne-terminated Oligonucleotide with a covalently bound redox probe to a monolayer of azide-terminated thiols on a gold electrode. Using this electrochemistry and the Scanning Electrochemical Microscope from our colleagues at Cal State Long Beach, this technique has the potential for significant diagnostic applications, both in genome screening, looking for specific sequences of DNA with potential for being binding sites for enzymes, and cancer detection because of its inherent ability to identify mutations in DNA sequences.