Abstract
A novel method for DNA surface immobilization and a paradigm for the attachment of unmodified DNA of any length or sequence are described herein. The development of a DNA self-assembled monolayer (DNA-SAM) that incorporates a DNA-thiol into a monolayer of inert alkane thiolates is reported. This DNA-SAM specifically hybridized complementary oligonucleotides while resisting the nonspecific adsorption of noncomplementary DNA and irrelevant proteins. Duplex DNA, having a single-stranded "capture tail," specifically bound to the DNA-SAM if the sequence of the "tail" was complementary to DNA presented in the SAM. The sense strand of the hybridized duplex DNA could be covalently attached to the surface by an enzymatic ligation reaction (leaving the anti-sense strand dissociable). DNA-binding proteins specifically bound to these surfaces only if their cognate sites were present in the duplex DNA.