Nanostructured vs. Carbonaceous Biosensors - Comparative Studies for Detection of Phenolic Compounds

Abstract

The biosensing properties of tyrosinase biosensors were investigated for two different immobilization matrixes: carbon paste and Langmuir-Blodgett thin film. In both cases the electron mediator was the lutetium (III) bisphthalocyaninate. The electrochemical responses of biosensors towards phenol and catechol were analyzed and compared. The tyrosinase maintains its bioactivity well within the immobilization matrices. A clearly defined reduction current proportional to the phenolic compounds concentration was observed in cyclic voltammetry, which attributed to the reduction of enzymatically produced quinone at the electrode surface. It was demonstrated that the biosensor based on LangmuirBlodgett thin film shows the best performances in terms of kinetics and detection limit for the phenolic