Preparation and Electrochemical Properties of Porous Platinum Electrode

Porous platinum electrodes were prepared by adding YSZ,as an active material,in platinum paste.Relationship between microstructure and electrochemical performance of O 2(g),Pt/YSZ electrode have been characterized by SEM and cyclic voltammetry.Results showed that the microstructure of platinum electrode is a significant impact on the cyclic voltammetry.With the increase of platinum electrode's porosity,the area of three-phase boundary of O 2(g) /Pt/YSZ was increased.The electrochemical reactivity was also enhanced.These were presented as the increase of current density and cathode voltage in cyclic voltammetry.

Tris(2,2'-bipyridyl)ruthenium(Ⅱ) electrochemiluminescence (ECL) enhanced by rutin on platinum electrode

Ru（bpy）3^2＋ electrochemiluminescence （ECL） was applied to determination of rutin. ECL intensity of Ru（bpy）3^2＋ could be enhanced in the presence of rufin in basic solution on platinum electrode. At pH 9.9, light emission intensity was found to be linear with rutin in the range of 1-50μmol/L.

Copper modified platinum electrode for amperometric detection of spectinomycin sulfate by anion-exchange chromatography

A La^3＋-Cu/Pt modified electrode was fabricated by electrodepositing process in CuS04 solution by adding a small amount of lanthium compound, and it was employed for direct current （DC） amperometric detection of spectinomycin by anion-exchange chromatography. Without derivatization, this method can simultaneously determine the main component and impurities in spectinomycin pharmaceutical raw material. Ease of preparation, being applied in DC detection mode and good catalytic stability confirmed the interests of this modified electrode as amperometric sensor for the determination of spectinomycin.

Plastic supported platinum modified nickel electrode and its high electrocatalytic activity for sodium borohydride electrooxidation

A novel plastic/multi-walled carbon nanotube（MWNTs）-nickel（Ni）-platinum（Pt） electrode（PMNP） is prepared by chemical-reducing Pt onto the surface of Ni film covered plastic/MWNTs（PM） substrate. The MWNTs are adhered by a piece of commercial double faced adhesive tape on the surface of plastic paper and the Ni film is prepared by a simple electrodeposition method. The morphology and phase structure of the PMNP electrode are characterized by scanning electron microscopy,transmission electron microscope and X-ray diffractometer. The catalytic activity of the PMNP electrode for Na BH4 electrooxidation is investigated by means of cyclic voltammetry and chronoamperometry. The catalyst combines tightly with the plastic paper and exhibits a good stability. MWNTs serve as both conductive material and hydrogen storage material and the Ni film and Pt are employed as electrochemical catalysts. The PMNP electrode exhibits a high electrocatalytic performance and the oxidation current density reaches to 10.76 A/（mg·cm） in 0.1 mol/dm3 Na BH4at0 V,which is much higher than those in the previous reports. The using of waste plastic reduces the discarding of white pollution and consumption of metal resources.

Abnormal IR Spectra of CO Adsorbed on the Surface of Glass Carbon Electrode Modified with Polypyrrole Film with Platinum Microparticles

Abnormal IR spectra of CO adsorbed at the surface of glass carbon electrode modified with polypyrrole film with Pt microparticles are reported.

Preparation of the Ag_2O_2-PbO_2 Modified Electrode and Its Application towards Escherichia coli Fast Counting in Water

A novel nano crystalline Ag2O2-PbO2 film chemically modified electrode (CME) was prepared and the CME was characterized by X-ray diffractometer (XRD) and atomic force microscope (AFM). By chronoamperometry, the nano Ag2O2-PbO2 CME was used as bioelectro- chemical sensor to determine the population of Escherichia coli (E. coli) in water. Compared with conventional methods, it is found that the technique we used is fast and convenient in counting E. coli.

Thin-layer Spectroelectrochemistry of 3,3′,5,5′-Tetramethyl-benzidine on Pt Minigrid Optically Transparent Electrode

The electrooxidation behavior of 3, 3′,5, 5′-tetramethylbenzidine(TMB) was investigated using a platinum minigrid optically transparent thin-layer spectroelectrochemical cell. TMB underwent one two-electron electrooxidation process to yield quinonediimine in the pH range from 2.0 to < 4.0, and two consecutive one-electron electrooxidation processes, gave the mediate product free radical of TMB first, then gave the oxidation product quinonediimine in the pH range from 4.0 to < 7.0. In the pH range from 7.0 to 10.0, the electrooxidation of TMB was also one two-electron electrooxidation process to yield an azo compound. The formal potential E0'and the electron transfer number of the electrooxidation of TMB at pH 2.0 and pH 8.4 were determined by spectroelectrochemical techniques.

The Determination of Iodide Based on a Flow-injection Coupling Irreversible Biamperometry

A novel flow-injection irreversible biamperometric method is described for the direct determination of iodide. The method is based on electrochemical oxidation of iodide at the gold electrode and the reduction of permanganate at the platinum electrode to form an irreversible biamperometric detection system. Under the applied potential difference of 0 V, in the 0.05 mol/L sulfuric acid, iodidecan be determined over the range 4.00×10^-7-1.00×10^-5 mol/L with a sampling frequency of 120 samples per hour. The detection limit for I- is 3.0×10^-7 mol/L and the RSD for 40 replicate determinations of 4.0×10^-5 mol/L potassium iodide is 1.68%. The new method was applied to the analysis of iodide in table salt with satisfactory results.

Determination of levodopa in pharmaceutical preparations by irreversible biamperometry

Based on the electrocatalytic oxidation of levodopa at gold electrode and the reduction of permanganate at platinum electrode, a novel flow injection irreversible biamperometric method is developed for the determination of levodopa under the potential difference of 0 V imposed between two electrodes. In H2SO4 solution, the linear relationships between currents and the concentrations of levodopa are obtained in the range from 0.04 mg/L to 20 mg/L with the detection limit of 0.012 mg/L. The proposed method is applied to the determination of levodopa in pharmaceutical preparations.

Determination of Ammonium Ion in Lake Water by Voltammetry

An electroanalytical method for the determination of ammonium ion using a platinized platinum electrode is described. Under optimized analytical conditions, the linear range of the calibration graphs for ammonium ion is 3.0×10?5?5.0×10?3 mol·L?1 with a detection limit of 5.0×10?6 mol·L?1. The method has been applied to the determination of ammonium ion in lake water samples and recoveries of 100%–103% are obtained. The results obtained are found to be in good agreement with spectrophotometric results. Key words ammonium ion - voltammetry - platinized platinum electrode CLC number O 657.1 Foundation item: Supported by the National Natural Science Foundation of China (60171023)Biography: Wu Yun-hua (1971-), female, Ph. D candidate, research direction: bioelectrochemistry.

Highly sensitive potentiometric immunosensor for hepatitis B surface antigen diagnosis

A highly sensitive potentiometric immunosensor for the diagnoses of epidemic dis-eases has been developed by means of self-assembly to immobilize hepatitis B surface antibody(HBsAb)for the detection of hepatitis B surface antigen(HBsAg)as a model.At first,the Nafion containing-SO^(-)_(3)groups was immobilized on a platinum electrode surface to absorb the-NH^(+)_(3)groups of antibody molecules via the opposite-charged adsorption technique,in the meantime,hepatitis B surface antibodies were adsorbed onto the surface of Au nanoparticles,then hepatitis B surface antibodies and Au nanopartilces were entrapped into polyvinyl butyral on the surface of Nafion film.The modified procedure was further characterized by electrochemical impedance spectroscopy(EIS)and cyclic voltammetry(CV).The influence and factors influencing the per-formance of resulting immunosensor were studied in detail.The resulting immunosensor exhib-ited sigmoid curve with log HBsAg concentrations,high sensitivity,wide linear range from 26 to 1280 ng·mL^(-1)with a detection limit of 3.1 ng·mL^(-1),rapid potentiometric response(<3 min)and long-term stability(>4 months).Analytical results of clinical samples show that the developed immunoassay is comparable with the enzyme-linked immunosorbent assays(ELISAs)method,implying a promising alternative approach for detecting HBsAg in the clinical diagnosis.