Ionic liquid/mesoporous carbon/protein composite microelectrode and its biosensing application

A functional composite was prepared by mixing mesoporous carbon, glucose oxidase (GOD) and 1-butyl-3-methylimidazolium hexafluorophosphate, an ionic liquid, and characterized by SEM and RA-IR. The composite was filled in a microcavity to fabricate a paste microelectrode, demonstrating direct electrochemistry of GOD with a pair of well-defined redox peaks. The composite microelectrode was used as a glucose microsensor, showing good sensitivity over a concentration range from 10.0 to 80.0 μmol/L and a Michaelis–Menten constant of 2.42 μmol/L. This work demonstrates an efficient and accurate approach to study direct electrochemistry with potential applications in various enzymatic biosensors.