Direct Electrochemistry of Hemoglobin and Its Electrocatalysis Based on Hyaluronic Acid and Room Temperature Ionic Liquid

A biocomposite material of hyaluronic acid (HA) and room temperature ionic liquid, 1-butyl-3-methyl-imidazolium tetrafluoroborate (BMIMBF4) was fabricated and characterized by voltammetry and electrochemical impedance spectroscopy. Hemoglobin (Hb), as a model protein, was immobilized in this biocomposite on glassy carbon electrode to investigate its direct electrochemistry A pair of well-defined, quasireversible cyclic voltammetric peaks appeared with the formal potentials (E-o1) at -0.360V (vs. SCE). The Hb modified electrode exhibited an excellent electrocatalytic activity to the reduction of H2O2, with a wide linear range, good selectivity, sensitivity and reproducibility, which had potential application to fabrication the third-generation biosensor.