The application of cytochromes as the interface molecule to facilitate the electron transfer for PQQ glucose dehydrogenase employing mediator type glucose sensor

In order to improve the sensor response of mediator-type glucose enzyme electrode, we focused on the application of the electron transfer proteins, cytochromes, as interface molecules to facilitate the electron transfer from enzyme to artificial electron mediator. In this paper we used cytochrome c and cytochrome b(562) for the improvement of sensor signal of glucose enzyme sensor employing glucose dehydrogenase harboring pyrroloquinoline quinone (PQQGDH). When sensors were operated using either potassium ferricyanide or 1-methoxy-5-methylphenazinium methylsulfate (mPMS) as the artificial electron mediator, the response was over 30-fold greater with the co-immobilization of either cytochrome c or cytochrome b(562) than with PQQGDH alone. The impact of the cytochrome co-immobilization was dependent on the amount of cytochromes, indicating that these cytochromes facilitated the electron transfer from the PQQGDH redox center to the artificial electron mediators used in the sensor system. These results demonstrated the future application of cytochromes as an essential component for the improvement of sensor response in the redox enzyme-based amperometric sensors.