Adenine-uridine base pairing at the water-solid-interface

The formation of the base pair adenine-uracil at a water- solid interface, at an immobilized monolayer of adenine disulfide with adenine groups expose d to the very surface, respectively, is shown here. To overcome the steric hindrance of tightly packed adenine groups in a pure adenine thiolate monol ayer on gold, the formation of self-assembled monolayers out of a binary mi xture of the adenine disulfide and CH3- or OH-terminated thiols are investi gated. Electro-chemical investigations, surface plasmon spectroscopy (PSP, plasmon surface polariton), multimode waveguide-PSP-coupling spectroscopy, contact angle measurements, and spontaneous desorption time-of-flight mass spectrometry were used to characterize the monolayers. The specific base pa iring was investigated for a variety of monolayer compositions. A specific base pairing was successful for an optimized mixed adenine/OH-terminated th iol monolayer. Nevertheless unspecific binding is a problem.