New copolymers of N,N-dimethylacrylamide with blocked isocyanates for oligonucleotide immobilization in DNA microarray technology

A family of copolymers of N,N-dimethylacrylamide containing blocked isocyanate functionalities is presented. The copolymers were characterized by DSC, GPC and 1H NMR. Calorimetric analysis showed for any composition broad endothermal phenomena followed by a stronger exothermal peak, which can be attributed, respectively, to the deblocking and subsequent reaction of generated NCO groups. terization of glass slides coated with these polymers was done by contact angle measurements and atomic force microscopy. While the former method revealed minimal differences with formation of moderately hydrophilic surfaces, microscopic images showed a more homogeneous coating formation for the copolymer structure with 50% molar of blocked isocyanate. The efficiency of the coated substrates in the immobilization of amino functionalized oligonucleotides was successfully assessed through binding tests and analysis by confocal fluorescence microscopy. y, some model microarrays were fabricated by spotting and hybridization with complementary, fluorescently labelled targets was carried out. It resulted in surfaces coated with copolymers which show well defined circular spots with a fluorescence intensity higher than that obtained by slides treated by silanization, and based on the same immobilization chemistry.