Study On The Anti-adsorption Microarray Based On Zwitterionic Polymers

In view of the nonspecific adsorption of protein microarrays in the analysis of biological samples, zwitterionic polymers with ultra-low fouling property were grafted on the surface of protein microchips. Grafting procedures were optimized and the zwitterionic polymer surfaces were characterized. Furthermore, microarray patterns with various dimentions were fabricated. The region-selective patterning of microarrays were adopted, by which, the protein microarrays showed high detection sensitivity and anti-biofouling property.In our work, borosilicate glasses were used as the substrate for microarray fabrication. First, methacryloxypropyltrimethoxysilane (MAPTMS) hydrolyzed on treated surfaces, then the double bonds on the surfaces reacts with zwitterionic monomers——methacrylic sulfo-betaine and methacrylic acid carbo-betaine by UV initiated free radical polymerization. Modification conditions were discussed, the best results were achieved when using methanol/H2O as solvent, with a monomer concentration of80g/L, and a exposure intensity of14mW/cm2for5min.CBMA and SBMA were modified onto the substrate according to designed microarray patterns by selective exposure procedure. The array region of the protein microchip can be functionalized due to the conjugation between EDC/NHS and carboxy group of CBMA. FITC-BSA was chose as a model protein to test the nonfouling property of this protein microchip. Sheep anti-BSA and FITC-BSA were used as models to test the ability of the specific protein recognition and detection. Experiments showed that microarray surfaces have excellent nonfouling property, and the array area can make specific binding with0.1mg/mL FITC-BSA. Moreover, experiments also showed that zwitterionic microarray can direct cell adhesiveness by restricting the cell patterning area.