| Since the 1970's, chemically modified electrode (CME) has had a dominant position in the study of electrochemistry and electroanalytial chemistry. The distinguishing feature of CME is that the surface of electrode is coated with selected groups, which is to give new and specific properties in the chemical and electrochemical field. CME has been widely used in environmental and biological research, because it has the characteristics such as simple fabrication, high sensitivity, high selectivity, rapid, online analysis, etc. In this work, the principal research is the electrochemical behavior of hydrogen peroxide on the CME.The primary research work is as follows:1. Study on the electrochemical behavior of hydrogen peroxide based on Prussian blue electrodeposited on (3-mercaptopropyl)-trimethoxysilane polymer modified gold electrodeA hydrogen peroxide (H2O2) sensor was developed by electrodepositing Prussian blue (PB) on a gold electrode modified with (3-mercaptopropyl)-trimethoxysilane (MPS) polymer. The characterization of the self-assembled electrode was investigated by cyclic voltammetry and electrochemical impedance spectroscopy. The results of electrochemical experiments showed that such constructed sensor had a favorable catalytic ability to reduction of H2O2. The MPS film on the modified gold electrode greatly enhanced the pH adaptive range of PB. Large surface-to-volume ratio property of double-layer 2d-network MPS modified PB electrode has enabled stable and highly sensitive performance for the non-enzymatic H2O2 sensor. The linear range of H2O2 determined is from 2.0×10-6 to 2.0×10-4 mol L-1 with the correlation coefficient of 0.9991 and the detection limit for H2O2 is 1.8×10-6 mol L-1. The influences of the potentially interfering substances on the determination of H2O2 were investigated. This modified electrode exhibits a good selectivity and high sensitivity with satisfactory results.2. Hydrogen peroxide sensor based on Prussian blue analogue doped with Cd(Ⅱ) electrodeposited on the self-assembled (3-mercaptopropyl)-trimethoxysilane gold electrodeA hydrogen peroxide (H2O2) sensor was developed by electrodepositing Prussian blue analogue doped with Cd(Ⅱ) on a gold electrode modified with (3-mercaptopropyl)-trimethoxysilane (MPS) polymer. Several techniques, including cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy were employed to characterize the assembly process and performance of the sensor. The results of electrochemical experiments showed that such constructed sensor had a favorable catalytic ability to reduction of H2O2. The effect of thickness and pH for the Prussian blue analogue doped with Cd(Ⅱ) were studied. Large surface-to-volume ratio property of modified electrode has enabled highly sensitive performance for the non-enzymatic H2O2 sensor. The linear range of H2O2 determined is from 5.0×10-6 to 2.7×10-4 mol L-1 with the correlation coefficient (r) of 0.9961 and the detection limit for H2O2 is 4.3×10-7 mol L-1. The influences of the foreign substances on the determination of H2O2 were also investigated. The present work supplied a promising test method for reliable and rapid determination of H2O2.3. Recognition of hydrogen peroxide at a macroporous silver film electrodeWe report on the elaboration of macroporous silver film electrode. The strategy to create macroporous silver film was based on the electrodeposition of silver into the interstitial spaces of templates formed by polystyrene (PS) latex spheres that had been self-assembled onto bare gold electrode. After electrodeposition of silver, the PS spheres were removed by dissolution in toluene to leave a macroporous silver structure. The controlled porosity of the electrode shows an increased internal electroactive area and a significantly improved electrochemical performance. The interconnected macroporous structure makes the sensor has higher functional density and larger surface area, and also enhanced mass transport. Several techniques, including cyclic voltammetry, chronoamperometry and scanning electron microscope were employed to characterize the assembly process and performance of the sensor. The macroporous silver electrode has much better electrocatalytic activity towards the reduction of hydrogen peroxide than the nonporous silver electrode. The application of this novel electrochemical sensor for the quantitative determination of hydrogen peroxide has been examined.4. Preparation of ordered macroporous Prussian blue film electrode for hydrogen peroxide sensor applicationHighly ordered macroporous Prussian blue (PB) film with spherical pores with diameters of 1μm was prepared by electrochemical deposition PB into the interstitial spaces of polystyrene (PS) spheres template formed by self-assembled on glassy carbon electrode. After electrodeposition of PB, the PS spheres were fully removed by dissolution in toluene to leave an ordered macroporous silver structure, and the size of spherical pores is determined by the diameter of the polystyrene latex particles used to prepare the template. The assembly process and performance of the macroporous PB membrane sensor were characterized by several techniques, including cyclic voltammetry, chronoamperometry and scanning electron microscope. The interconnected porous structure of PB with larger surface area can enhance the permeability of analytes. Therefore, the prepared macroporous PB membrane sensor presented an excellent catalytic activity towards the reduction of hydrogen peroxide. The influences of various foreign species including ascorbic acid (AA) and uric acid (UA) on the sensor were also investigated. As expected, this modified electrode exhibits good selectivity and high sensitivity.
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