Abstract: Hybrid biosensor for the detecting of lactose and glucose simultaneously was developed. This biosensor consisting of two electrodes was based on the nuclear pore films modified by the yeast broken liquid and H2O2 electrodes. Glucose oxidase (GOD) and β- galactosidase(GAL) were immobilized on the membranes by using the glutaric dialdehyde as crosslinking agent. Having studied the response characteristics of the two electrodes, the biosensor shows good linearity among the ranges of 0.2～ 2 g/100ml and 4～10 g/100ml of lactose and 0～100mg/100ml glucose respectively. The response time is less than 40s for lactose and less than 20s for glucose. The self(half-life)-life of the galactosidase-electrode is between 15 and 20 days while the glucose oxidase-electrode is more than 60 days. The interference of glucose in lactose detecting can be removed through the subtractive operation between the response datas of the two electrodes.

Key words: lactose biosensor, glucose biosensor, nuclear pore membrane, fragmentized liquid of the yeast