AMPEROMETRIC BIOSENSOR FOR TYROSINASE INHIBITORS IN A PURE ORGANIC-PHASE

The determination of benzoic acid, thiourea and 2-mercaptoethanol in t hree pure organic solvents, viz., chloroform, chlorobenzene and 1,2-di chlorobenzene, by using an amperometric cryohydrogel tyrosinase biosen sor is described. Measurements were carried out with phenol as the enz yme substrate. Kinetic parameters (K-i and I-50) were determined in th e three solvents for various inhibitors. The sensor showed the most se nsitive measurements to these inhibitors in pure chloroform. The solve nt-induced deviation of the biosensor to thiourea was evaluated by mea ns of Hill coefficients. The smallest deviation as observed in 1,2-dic hlorobenzene, owing to the high hydrophobicity of this solvent. The na ture of the inhibition process and its reversibility mere also examine d.