Covalent attachment of oligodeoxyribonucleotides to amine-modified Si (001) surfaces

A recently described reaction for the UV-mediated attachment of alkenes to silicon surfaces is utilized as the basis for the preparation of functional ized silicon surfaces, UV tight mediates the reaction of t-butyloxycarbonyl (t-BOC) protected omega-unsaturated aminoalkane (10-aminodec-1-ene) with h ydrogen-terminated silicon (001). Removal of the t-BOC protecting group yie lds an aminodecane-modified silicon surface. The resultant amino groups can be coupled to thiol-modified oligodeoxyribonucleotides using a heterobifun ctional crosslinker, permitting the preparation of DNA arrays, Two methods for controlling the surface density of oligodeoxyribonucleotides were explo red: in the first, binary mixtures of 10-aminodec-1-ene and dodecene were u tilized in the initial UV-mediated coupling reaction; a linear relationship was found between the mole fraction of aminodecene and the density of DNA hybridization sites. In the second, only a portion of the t-BOC protecting groups was removed from the surface by limiting the time allowed for the de protection reaction, The oligodeoxyribonucleotide-modified surfaces were ex tremely stable and performed well in DNA hybridization assays. These surfac es provide an alternative to gold or glass for surface immobilization of ol igonucleotides in DNA arrays as well as a route for the coupling of nucleic acid biomolecular recognition elements to semiconductor materials.