Reactive hydrogels grafted on gold surfaces

Three different strategies for the fixation of stable hydrogel coatings on gold surfaces, by the grafting-to and grafting-from techniques, are describ ed. Monomeric or polymeric disulfide initiators are employed to start the p hotopolymerization of N-[tris(hydroxy-methyl)methyl]acrylamide (1) under ba r via decomposition of azo compounds or via a photoredox system. Different approaches, based on the post functionalization of the poly((1) under bar) films or on copolymerization of reactive monomers with (1) under bar, are e mployed to bind potential receptor molecules bearing amino or thiol groups as anchor to the hydrogel. Thus, the functionalized coatings should allow t he selective binding of particular analyzates. The overall goal is focused on hydrogel films for the preparation of biochips used in analytical device s such as Surface Plasmon Resonance (SPR), though our approach seems to be generally useful for related purposes.