ELECTROCHEMICAL POLYMERIZATION OF FUNCTIONALIZED THIOPHENE DERIVATIVES FOR THE IMMOBILIZATION OF PROTEINS

The hydroxy group of 3-(2-hydroxyethyl)thiophene was protected as meth yl ether 1 and as dimethyl tert-butyl silyl ether 5 before anodic poly merization. The poly[3-(2-methoxyethyl)thiophene] 2 was prepared by el ectrochemical homopolymerization of 1. Ether cleavage was carried out in the polymer film 2 and the resulting poly[3-(2- hydroxyethyl)thioph ene] (3) was activated with cyanogen bromide to immobilize alcohol deh ydrogenase. Silylether 5 did not undergo homopolymerization but copoly merization of 5 with 3-methylthiophene (4) was successful. After cleav age of the protecting group the resulting copolymer 7 was activated by cyanuric chloride, and chymotrypsin was immobilized. Electrocopolymer ization of thiophene-3-acetic acid (8) and 3-methylthiophene (4) under various conditions produces copolymer 9. By activation of the carboxy lic groups with N,N'-dicyclohexylcarbodiimide (DCC) lactate oxidase (L OD) was bond to the surface of the electrode to form a lactate sensor.