Reliable amperometric determination of glycerol and glycerol-3-phosphate with a bienzymatic nylon membrane electrode

Abstract An enzymatic biosensor for glycerol and glycerol-3-phosphate was designed, based on the co-immobilization of two enzymes, glycerol kinase and glycerol-3-phosphate oxidase, on a nylon membrane activated by a process recently reported for nylon balls. Optimum conditions for immobilization, use and storage were defined. A detection limit as low as 7 × 10 −8 M for glycerol and 1 × 10 −7 M for glycerol-3-phosphate was obtained and assays could be performed in the linear ranges 1 × 10 −7 –5 × 10 −4 and 2 × 10 −7 –2 × 10 −3 M for glycerol and glycerol-3-phosphate, respectively. The response time is