▎ 摘　　要

In the study titanium dioxide (TiO2) doped three-dimensional graphene (3DGR) nanocomposite (TiO2@3D GR) was prepared via a one-step hydrothermal synthesis method. SEM results showed a three-dimensional network structure with TiO2 particles uniformly loaded in the graphene pores. Using PBS with different pH values as supporting electrolyte, the influence of acid-base property on the electrochemical experiments based on the proposed biosensor (Nafion/Mb/TiO2@3DGR/CILE) was investigated. The effect of sweep speed on electrochemical behavior was further explored. Nafion/Mb/TiO2@3DGR/CILE showed good electrocatalytic activity for trichloroacetic acid, NaNO2 and H2O2 with K-M(app) as 107.12 mM, 31.53 mM and 34.23 mM, obtaining wider range of linearity and lower limit of detection. The biosensor is of important significance for future research and development of electrochemical biosensor.