High surface density covalent immobilization of oligonucleotide monolayers

摘要

Oligonucleotides and other biomolecules are immobilized in high density on solid substrates through covalent forces using either a permanent thioether bond, or a chemoselectively reversible disulfide bond to a surface thiol. Substrates which have hydroxyl groups on their surfaces can be first silanized with a trichlorosilane containing 2-20 carbon atoms in its hydrocarbon backbone, terminating in a protected thiol group. The oligonucleotides or other biomolecules are first connected to a tether consisting of a hydrocarbon or polyether chain of 2-20 units in length which terminates in a thiol group. This thiol may be further modified with a halobenzylic-bifunctional water soluble reagent which allows the conjugate to be immobilized onto the surface thiol group by a permanent thioether bond. Alternatively, the oligonucleotide-tether-thiol group can be converted to a pyridyldisulfide functionality which attaches to the surface thiol by a chemoselectively reversible disulfide bond. The permanently bound oligonucleotides are immobilized in high density compared to other types of thiol functionalized silane surface and to the avidin-biotin method.