Electrochemiluminescence detection with integrated indium tin oxide electrode on electrophoretic microchip for direct bioanalysis of lincomycin in the urine

In this article, an antibiotic, lincomycin was determined in the urine sample by microchip capillary electrophoresis (CE) with integrated indium tin oxide (ITO) working electrode based on electrochemiluminescence (ECL) detection. This microchip CE-ECL system can be used for the rapid analysis of lincomycin within 40 s. Under the optimized conditions, the linear range was obtained from 5 to 100 muM with correlation coefficient of 0.998. The limit of detection (LOD) of 3.1 muM was obtained for lincomycin in the standard solution. We also applied this method to analyzing lincomycin in the urine matrix. The limit of detection of 9.0 muM was obtained. This method can determine lincomycin in the urine sample without pretreatment, which demonstrated that it is a promising method of detection of lincomycin in clinical and pharmaceutical area.

Electrochemistry and electrogenerated chemiluminescence of SiO2 nanoparticles/tris(2,2 '-bipyridyl)ruthenium(II) multilayer films on indium tin oxide electrodes

In this paper, a simple method of preparing {SiO2/Ru-(bPY)(3)(2+)}(n) multilayer films was described. Positively charged tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)(3)(2+)) and negatively charged SiO2 nanoparticles were assembled on ITO electrodes by a layer-by-layer method. Electrochemical and electrogenerated chemiluminescence (ECL) behaviors of the {SiO2/Ru(bpy)(3)(2+)}(n) multilayer film-modified electrodes were studied. Cyclic voltammetry, UV-visible spectroscopy, quartz crystal microbalance, and ECL were adopted to monitor the regular growth of the multilayer films. The multilayer films containing Ru(bpy)(3)(2+) was used for ECL determination of TPA, and the sensitivity was more than 1 order of magnitude higher than that observed for previous reported immobilization methods for the determination of TPA. The multilayer films also showed better stability for one month at least. The high sensitivity and stability mainly resulted from the high surface area and special structure of the silica nanoparticles.

Studies on microstructure bilayer film of ultrasonic dipped cadmium sulfide and d.c. sputtered indium tin oxide

A bilayer CdS/ITO film was obtained. The dipped CdS was grown by an ultrasonic colloid deposition (USCD) method. Microstructure of the CdS film made by USCD has a wider transmission range and a higher transmittance. Amorphous indium-tin-oxide (ITO) thin film was deposited using d.c. magnetron-sputtering at room temperature. The ITO films exhibited good conductivity and maximum transmittance of 94%. The CdS/ITO bilayer was investigated by means of GIXD (grazing incidence X-ray diffraction) at different incidence angles (alpha = 0.20-5.00degrees) and XRD. We discuss a model for the thin bilayer film. SEM and AFM show that homogeneous CdS films with a bar-shaped ultrafine particles and ITO film with nanometer structure. The mechanism of the bilayer CdS/ITO film is discussed.

Dependence of performance of organic light-emitting devices on sheet resistance of indium-tin-oxide anodes

The dependence of the performance of organic light-emitting devices(OLEDs) on the sheet resistance of indium-tin-oxide(ITO) anodes was investigated by measuring the steady state current density brightness voltage characteristics and the electroluminescent spectra. The device with a higher sheet resistance anode shows a lower current density, a lower brightness level, and a higher operation voltage. The electroluminescence(EL) efficiencies of the devices with the same structure but different ITO anodes show more complicated differences. Furthermore, the shift of the light-emitting zone toward the anode was found when an anode with a higher sheet resistance was used. These performance differences are discussed and attributed to the reduction of hole injection and the increase in voltage drop over ITO anode with the increase in sheet resistance.

Microchip capillary electrophoresis with an integrated indium tin oxide electrode-based electrochemiluminescence detector

This paper describes an indium tin oxide (ITO) electrode-based Ru(bPY)(3)(2+) electrochemiluminecence (ECL) detector for a microchip capillary electrophoresis (CE). The microchip CE-ECL system described in this article consists of a poly(dimethylsiloxane) (PDMS) layer containing separation and injection channels and an electrode plate with an ITO electrode fabricated by a photolithographic method. The PDMS layer was reversibly bound to the ITO electrode plate, which greatly simplified the alignment of the separation channel with the working electrode and enhanced the photon-capturing efficiency. In our study, the high separation electric field had no significant influence on the ECL detector, and decouplers for isolating the separation electric field were not needed in the microchip CE-ECL system. The ITO electrodes employed in the experiments displayed good durability and stability in the analytical procedures. Proline was selected to perform the microchip device with a limit of detection of 1.2 muM (S/N = 3) and a linear range from 5 to 600 muM.

Study on sensing properties of tin oxide CO gas sensor with low power consumption

In this paper, the fabrication method of a new type of carbon monoxide gas sensor based on SnOx with low power consumption and its sensing characteristics have been reported. The electric conductance of this type of sensor evolves oscillation form regularly when the sensor is exposed to low level of CO gas. The oscillation amplitude is directly proportional to the concentration of CO gas over a wide range. The effects of relevant factors. such as. humidity, temperature and interference gases on the sensor properties were examined. The sensing oscillation response mechanism was also discussed.

X-ray photoelectron spectroscopy and mass spectrum of organic tin compounds

The relationship between the chemical displacement of the binding energy and the different chemical environment for 12 organic tin compounds was studied by means of X-ray photoelectron spectronscopy. The different substituents in the compounds have influence on the tin outer electron and Sn-O bond, which was discussed by Xray photoelectron spectroscopy and mass spectrum.

The influence of muffin-tin approximation on energy band gap

The influence of muffin-tin approximation on energy band gap was studied using LMTO-ASA (Linear Muffin-Tin Orbital-Atomic Sphere Approximation) approach. Since the diverse data are available for LaX(X=N, P, As, Sb), they are presented in our research as an example in order to test the reliability of our results. Four groups of muffin-tin radii were chosen, they were the fitted muffin-tin radii based on the optical properties of the crystals (the first), 1 : 1 for La : X(the second), 1.5 : 1 for La : X(the third), and a group of radii derived by making the charge in the interstitial space to be zero(the fourth). The results show that the fitted muffin-tin radii (the first group) give the best results compared with experimental values, and the predicted energy band gaps are very sensitive to the choice of muffin-tin radius in comparison with the other groups. The second and the third delivered results somewhere in between, while the fourth provided the worst results compared with the other groups. For the same crystal, with the increase of muffin-tin radius of lanthanum, the calculated energy band gaps decreased, going from semi-conductor to semimetal. This again clearly indicated the sensitivity of energy band structure on muffin-tin approximation.

The study of immersion chloride extraction of iron artifacts

The chloride extraction rules of iron artifacts were studied by immersion methods. Different chloride extraction results between the alkaline solution and a washing solution were obtained. The microstructure and the anti-corrosion performance of the samples before and after treatment, were, respectively studied by the scanning electron microscope (SEM) and the potentiodynamic scanning method. The results indicated that Cl- removed according to the diffusion law. The microstructure of the samples transformed after treatment. The rusts became more compact, and the porosity also increased. The chloride extraction effect in the washing solution was better than that in the NaOH solution.