Synthesis and Characterization of Nano Polyaniline Laccases Enzyme Based Biosensor

Abstract

Biosensors can be defined as an analytical tool or system consisting of an immobilized biological material in intimate contact with a suitable transducer. In this study White Laccases from Pleurotus ostreatus were used to develop a biosensor for determining phenols in effluents.The polyaniline was electrochemically synthesized by using an electrochemical cell consisting of working ITO glass (anode) and secondary electrodes of stainless steel (cathode) and saturated calomel electrode as reference electrode. Polymerization was carried out potentiodynamically using a potentiostat/galvanostat. This electrosynthesized PANI film served two purposes when applied in this biosensor. It behaved as an electron mediator, shuttling electrons between the immobilized enzyme and the electrode surface and also served as a point of attachment for the protein Laccases. The polyaniline thin films were characterized by using UV-VIS spectrophotometer, FT-IR spectrophotometer, Xray diffraction and scanning electron microscope. The properties of prepared Laccases enzyme modified polyaniline based electrodes were studied by FTIR, UV-vis spectrophotometer, SEM. Biosensing response was studied by Potentiostat/galvanostat and Potentiostat using an electrolysis cell consisted of two platinum foils and a saturated calomel electrode. The minimum concentration of phenol that could be studied with this biosensor was 2.5×10-4 M.