▎ 摘　　要

Graphene (GR) and bismuth (Bi) film was directly electrodeposited on carbon ionic liquid electrode (CILE) surface, which was applied as the substrate electrode. Myoglobin (Mb) was fixed on the Bi/GR/CILE surface with a thin Nafion membrane to get a new electrochemical biosensor (Nafion/Mb/Bi/GR/CILE). Cyclic voltammetric results showed that a couple of well-defined redox peaks present on the voltammograms, exhibiting the achievement of direct electron transfer of Mb on the electrode. This result can be attributed to the existence of GR and Bi film with high electronic conductivity and big surface area. Electrochemical parameters were got with electron transfer coefficient (alpha) as 0.34 and heterogeneous electron transfer kinetic constant (k(s)) as 1.15 s(-1). This Mb modified electrode reveals fine electrocatalytic activity to the reduction and detection of trichloroacetic acid (TCA) in the linear range from 0.5 to 46.0 mmol L-1 with the detection limit of 0.167 mmol L-1 (3 sigma). Therefore a promising electrochemical biosensor was constructed successfully.