Zhihui Wen, Daoxin Lju, Baoxian Ye and Xingyao Zhou
A new type of disposable electrochemical sensor, which consists of a piece of Nafion membrane and a microdisk electrode, is developed. The Nafion membrane, which is butted by the electrode to actualize the electrochemical reaction, acts as the immobilization bed for mediator (anthraquinone) and enzyme (glucose oxidase). The sensor is not vulnerable to being broken or contaminated. By replacing the immobilization beds with different mediators and different enzymes in series, the sensor may be employed for the rapid analysis of a multi-component sample. The sensor exhibits a rapid, stable response to glucose. A consecutive calibration test shows that the original tip has an active period greater than 24 hours and the storage life time longer than 3 weeks. The linear range and the sensitivity of the original sensor are 6 mM and 0.52 nA/mM, respectively.