Direct Electron Transfer of Catalase and its Biosensing for H2O2

By immobilizing catalase on a functional nanocomposites containing ion-liquid, TiO2 nano particles and carboxylic acid functionalized multi-walled carbon nanotubes, direct electron transfer of CAT was realized on the nanocomposites modified glassy carbon electrode. The electrochemical study showed that the formal potential and heterogeneous electron transfer constant of the prepared modified glassy carbon electrode were −0.163 V and 5.24 s−1, respectively. The electrocatalysis study showed that the linear response range toward H2O2 and the apparent Michaelis–Menten constant were from 5 μM to 1000 μM and 54.3 μM, respectively.