Aminoazopolymers with the capability of photoinduced immobilization developed for protein Arrays with low photoluminescence

We synthesized polymers containing three different kinds of azobenzene moiety, namely, 4-amino-4'-nitroazobenzene (NO2-azopolymer), 4-amino-4'-cyanoazobenzene (CN-azopolymer), and aminoazobenzene (H-azopolymer), and investigated them for application in high-performance protein arrays with the capability of photoinduced immobilization. Proteins can be immobilized on the surfaces of all these azopolymers by irradiation with visible light, and their functionality can be maintained once they are immobilized on the surface. We compared the detection limits for the fluorescent dyes Cy5 and Cy3 on films of the azopolymers. Of the three, the H-azopolymer showed the highest sensitivity for detection of both fluorescent dyes, with detection limits of about 5 pg/mL for each dye. We estimated the inherent fluorescence intensity of the azopolymer films and confirmed that the inherent fluorescence of each azopolymer moiety was the main factor affecting the detection limit.