Selective determination of cholesterol based on cholesterol oxidase-alkaline phosphatase bienzyme electrode.

A bienzyme electrode for the determination of cholesterol was prepared by the co-immobilization of cholesterol oxidase and alkaline phosphatase (ALP) on the carbon nanotubes modified electrode surface. The parameters influenced the performance of the bienzyme electrode such as the pH of the base solution; the concentration of DPP and the incubation time, were optimized. A linear calibration graph in the 0.05-2.0 mM concentration range with the sensitivity of 4.65 μA mM(-1) was obtained. In addition, this work provides a new interferent-depleted method and universal protocol for the design of multi-enzyme biosensors.