Electrochemical investigation on the catalytic ability of tyrosinase with the effect of nano titanium dioxide

Tyrosinase, which is also named poly-phenol oxidase, has the ability to oxidize several kinds of phenolic compounds to homologous o-quinones. In this work, nano titanium dioxide particles (TiO2 NPs) and tyrosinase are co-immobilized onto the surface of glassy carbon electrode to electrochemically study the effect of TiO2 NPs on the catalytic activity of tyrosinase. And, the influence of the photovoltaic effect of this nanomaterial on the catalytic ability of this enzyme is especially investigated. It is found that TiO2 NPs can greatly enhance the catalytic ability of tyrosinase. Moreover, the photovoltaic effect of this nanomaterial can further make tyrosinase to exhibit a higher enzymatic activity. This phenomenon may be due to the increasing amount of oxytyrosinase generated by the photovoltaic effect under ultraviolet (UV) light irradiation, which is an important intermediate in the process of the catalytic reactions. (C) 2006 Elsevier B.V. All rights reserved.