Electrochemical Investigation And Application Of Novel Polymer Films And Room Temperature Ionic Liquids

Owing to its cost-effectiveness, facility and simplicity in modification, polymer films have been applied in many research fields, such as life science, environmental control, medicine engineering, energy source, etc. This thesis concentrated on the combination of electrochemically polymerized film and polyelectrolyte film with electron mediators, polyoxometalates and nanoparticles. The resulted new polymer films were used to modify electrodes and applied in electrocatalysis and biosensor. On the other hand, room temperature ionic liquids (RTILs) as a kind of"green solvent"has received increasing attention. Thus, this thesis also focused on the primary application of RTILs in bioelectrochemistry and capillary electrophoresis. The main points of this thesis are summarized as follows:(1) A new H2O2 biosensor based on hemoglobin (Hb) and quinhydrone (QHQ) entrapped into poly(o-aminophenol)(POAP) film was constructed. POAP, Hb-POAP and Hb-QHQ-POAP films were characterized by piezoelectric quartz crystal impedance technique, and their thicknesses were estimated. The QHQ mediation effects on the electrocatalytic performance of Hb were investigated by using cyclic voltammetry, amperometry and kinetic study. Results showed that redox peaks of Hb-QHQ-POAP film were much more reversible than those of Hb-POAP film. The response current of Hb-QHQ-POAP film to H2O2 was almost twice than that of Hb-POAP film. The Michaelis-Menten constant and activation energy of Hb in Hb-QHQ-POAP film are 7.47 mmol?L-1 and 13.91 kJ?mol-1, respectively. These values are smaller than those in Hb-POAP film.(2) A novel H2O2 biosensor based on immobilization of Hb in conducting quasi-Prussian blue (iron-cobalt hexacyanoferrates, FeCoHCF) and POAP films was fabricated by cyclic voltammetry. FeCoHCF films deposited from solutions with different molar ratios of iron were studied by cyclic voltammetry and energy dispersive X-ray spectroscopy, and their solid states were characterized by Fourier transform infrared spectroscopy. POAP film was selected and used to improve the stability of the modified electrode. The permselectivity of POAP film to various redox ions was discussed in detail. Amperometric response of Hb/POAP/FeCoHCF film to H2O2 was investigated and compared with those of Hb/POAP and POAP/FeCoHCF films. The former is almost 40 and 1.5 times than that of the latters. Response current of...