Synthesis and utilization of Co₃O₄ doped carbon nanofiber for fabrication of hemoglobin-based electrochemical sensor

In this paper cobalt oxide (Co₃O₄) nanoparticles were mixed with polyacrylonitrile to prepare Co₃O₄ doped carbon nanofiber (CNF) composite by electrospinning and carbonization, which was further used to modify on carbon ionic liquid electrode (CILE). Hemoglobin (Hb) was immobilized on Co₃O₄-CNF/CILE surface with Nafion acted as the protective film to fabricate an electrochemical biosensor (Nafion/Hb/Co₃O₄-CNF/CILE). Electrochemical behavior of Hb on the electrode was investigated with a pair of quasi-reversible redox peak appeared on cyclic voltammogram and electrochemical parameters were calculated. Moreover, this biosensor had good analytical capabilities for electrocatalytic reduction of different substrates including trichloroacetic acid, potassium bromate and sodium nitrite with wider detection range from 40.0 to 260.0 mmol L^-1, 0.1 to 48.0 mmol L^-1 and 1.0 to 12.0 mmol L^-1 by cyclic voltammetry, respectively. The proposed method showed excellent anti-interferences ability with good selectivity and was successful used for quantitative detection of real samples, which displayed the potential applications to develop into a new analytical device.