Département de chimie moléculaire

A photoactivable org. polymer was prepd. first by electrogeneration of a conductive biotinylated polypyrrole film in acetonitrile electrolyte. The successive anchoring of avidin and photobiotin led to a multilayer configuration. The latter was illuminated with light (wavelength 370-400 nm) in the presence of proteins adsorbed onto its surface. The irradn. allowed the covalent linking of the proteins to the modified electrode. As a result of the photochem. reaction, a monolayer of enzyme (glucose oxidase, GOX or alk. phosphatase, AP) was covalently bound to the photobiotin-modified surface with retention of their catalytic activities. The surface activities were 34 and 1.69 mU cm-2 for GOX and AP photobiotin electrodes, resp. These enzyme electrodes were compared to similar configurations obtained through the immobilization of biotinylated glucose oxidase or avidin-conjugated alk. phosphatase on biotinylated polypyrrole film. The authors' results suggest that both procedures led to the immobilization of the same enzyme amt., namely a protein monolayer. This novel photo-immobilization methodol. was also successfully applied to the anchoring of an anti-cholera toxin antibody which was then detected by a secondary antibody labeled with a peroxidase. [on SciFinder(R)]