Electrochemical Detection of Alkaline Phosphatase Using Ionic Liquid Modified Carbon Nanotubes Electrode

An electrochemical method to continuously detect alkaline phosphatase (AP) was developed. Using home-made ionic liquid modified carbon nanotubes electrode (CNTs-ILE), on the basis of the characteristics of CNTs-ILE and the substrate p-nitrophenyl phosphate (PNPP) and product p-nitrophenol (PNP), the continuous detection of the process of AP enzymatic reaction with amperometry was achieved. The results indicated that the cyclic voltammetry feature of the CNTs-ILE was superior to conventional glassy carbon electrode, also a good anti-passivation characteristic was achieved for the detection of PNP. When the concentration of AP was in the range of 1.0 −100 U L−1, the current showed a good linear relationship to the concentrations of AP. This method was quick to detect AP, and detection time was less than 20 min.