Study on immobilization of enzyme and electron mediator for the detection of phenol

Abstract

We developed a novel electrochemical method to detect phenol using the ferrocenyl-tethered dendrimer and enzyme, tyrosinase. Here, we use the ferrocenyl-tehered dendrimer as a building unit and electron transfer mediator. Fc-D provides an efficient binding site for immobilizing enzyme onto the electrode, and acts as an electrocatalyst to shuttle electrons between the electroactive products generated by enzymatic reaction and the Au electrode. We use the enzyme, tyrosinase, to oxidize phenol to catechol, which in turn is oxidized to o-quinone. According to the cyclic voltammetry, we observe that the oxidation peak current is increased as phenol concentration is increased in the phosphate buffer solution. To enhance the sensitivity, we constructed a multilayer assembly of tyrosinase and Fc-D on the Au electrode step by step. Our novel method may be useful as the electrochemical detection method for phenol in the environments and it seems that the enzyme electrode sensitivity directly controllable, and the multilayer-forming strategy with partial ferrocenyl-tethered dendrimer is useful for the fabrication of biosensor.