Fabrication of carbohydrate microarrays on a poly(2-hydroxyethyl methacrylate)-based photoactive substrate.

We report the fabrication of carbohydrate microarrays on a photoactive polymer, poly(HEMA-co-HEMA-PFPA), synthesized by RAFT copolymerization of 2-hydroxyethyl methacrylate (HEMA) and perfluorophenyl azide (PFPA)-derivatized HEMA (HEMA-PFPA). PFPA allows the covalent immobilization of carbohydrates whereas the HEMA polymer provides an antifouling surface, thus the microarrays can be used directly without pretreating the array with a blocking agent. The microarrays were prepared by spin-coating the polymer followed by printing the carbohydrates. Subsequent irradiation simultaneously immobilized the carbohydrates and crosslinked the polymer matrix. The obtained 3D carbohydrate microarrays showed enhanced fluorescence signals upon treating with a fluorescent lectin in comparison with a 2D microarray. The signals were acquired at a lower lectin concentration and a shorter incubation time. When treated with E. coli bacteria, the carbohydrate microarray showed results that were consistent with their binding patterns.