(16a) Reagentless DNA Bioconjugation to Metal Surfaces

DNA is unique in its abilities to both self-assemble and recognize other biomolecules. These traits have enabled its application in a variety of fundamental scientific and medical devices. Most DNA platforms depend on thiol groups to tether DNA to gold surfaces, but this method suffers from the lack of control over DNA assembly. We have developed a reagentless, one-pot bioconjugation reaction to attach oligonucleotides to gold surfaces based on electrochemical oxidation. Coupling proceeds in minutes at low micromolar DNA concentrations, and, importantly, we can control the final DNA surface coverage by varying the reaction time and underlying thiol monolayer content. We have shown the widespread applicability of this method by electrochemically detecting the endocrine disruptor bisphenol A and by specifically capturing living nonadherent cells through DNA hybridization. This method has shifted the paradigm of DNA attachment to metal surfaces and represents a new direction for selective biomolecule attachment to surfaces.