Detection of trace phenol based on mesoporous silica derived tyrosinase-peroxidase biosensor

A novel electrochemical biosensor for phenol based on immobilization of tyrosinase-peroxidase on mesoporous silica is described. The enhanced sensitivity of the tyrosinase-horseradish peroxidase based biosensor to phenol was observed on comparing with tyrosinase or horseradish peroxidase monoenzyme modified electrodes. Two enzymes retained their enzymatic activities for phenol determination without any mediator. The preparation conditions of the biosensor are discussed. Optimization of the experimental parameters was performed with regard to pH and operating potential. The phenol sensor exhibited a fast response of less than 10 seconds. The sensitivity of the biosensor for phenol was 14 mu A mu M-1 cm(-2) with a linear range from 2 x 10(-7) to 2.3 x 10(-4) M and a detection limit of 4.1 x 10(-9) M. The biosensor showed a good stability and reproducibility.