(55f) Electrochemical Activation for DNA Attachment to Surfaces

The ability to selectively attach biopolymers, including DNA and peptides, to surfaces is imperative for biological research. Of great interest is their specific placement on gold surfaces. While thiol self-assembly has been the standard for DNA assembly, it provides little control over the resulting thin film. Chemical coupling strategies to pre-formed monolayers enable more control but can require electrochemically active catalysts or reagents. These methods also make the amount of biopolymer deposited and its deposition location difficult to control. We have developed a reagentless coupling method to electrochemically attach biopolymers to surfaces using the specific oxidation of a catechol to a particular electrode. With our method, commercially-available DNA is rapidly attached to surfaces, yielding complete coupling within minutes. Furthermore, we have full control over the amount of biopolymer on the surface, which can be tailored to the specific application of the device. Using this attachment method, we have formed whole cell-based thin films. Additionally, we have optimized the platform for the specific detection of the endocrine disruptor bisphenol A (BPA), a problematic additive to plastics, using a DNA aptamer on the surface.