A biosensor that combines electrochemistry and calorimetry was investigated. Using this sensor, glucose measurements were performed by employing glucose oxidase together with ferrocene as electron-transfer mediator. The electrochemical reaction was accomplished by applying a voltage between a platinum column (working electrode), in contact with a crushed reticulated vitreous carbon (RVC) matrix onto which glucose oxidase was immobilized, and platinum wires (counter electrodes) located at the inlet and outlet of the column. For detection, the thermal signal generated by the redox reaction was measured as opposed to measuring the electrochemical signal. By using this method, a linear range of glucose concentration up to 20 mmol l–1 was achieved.