Dissertation > Mathematical sciences and chemical > Chemistry > Analytical Chemistry > Instrument analysis ( physics and physical chemistry ) > Electrochemical analysis

Preparation and Electrochemical Sensor Application of Tansition Metal Hexacyanoferrate Modified Electrode

Author ShenRongXing
Tutor FangBin
School Anhui Normal University
Course Analytical Chemistry
Keywords Transition metal hexacyanoferrate Nanotechnology Modified electrodes Electrochemical sensors Hydrazine L-cysteine Dopamine Hydrogen peroxide
CLC O657.1
Type Master's thesis
Year 2010
Downloads 52
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The structure of tansition metal hexacyanoferrate is three-dimensional inorganic polymer network structure, in low-density, easy-doped solvent and the measurement of the number of variable, and many other aspects of these compounds are similar to the cross-linked organic polymer. In addition, it has a zeolite properties. In recent years, transition metal iron cyanide film modified electrode due to its excellent electrochemical reversibility, high stability, easy preparation, etc., are widely used in molecular recognition, photoelectric conversion, electrocatalysis, electrochromic, ion choice, anti-corrosion, biological sensing and so on. In this paper, several metal hexacyanoferrate and its compounds have been synthesized and modified electrode used for the electrochemical determination of hydrazine, L-cysteine, dopamine, hydrogen peroxide were fabricated. It may provid a good example of applying the good catalysis to electrochemistry.First of all, we have successfully fabricated Crhf nanoparticles attached SWMT and MWNTs surface. The morphological characterization of nanocomposites were examined by scanning electron microscopy (SEM), UV-vis spectroscopy, and Fourier transform infrared spectra (FT-IR). When the glassy carbon electrode was modified by the prepared adduct to form a modified electrode, the electrode showed a dramatically enhanced electrocalytic property toward hydrazine and L-cysteine due to the large specific surface area of CNTs and the accelerated electron transfer prompted by the stable and strong stacking interaction between Crhf and CNTs. The study found that the modified electrode has a high chemical stability and sensitivity.Secondly, A novel route for the fabrication of neodymium hexacyanoferrate (NdHCF) modified glassy carbon electrodes (GCE) was proposed. The morphological characterization of NdHCF was examined by scanning electron microscopy (SEM) and Fourier transform infrared spectra (FTIR). The performances of the NdHCF/GCE were characterized with cyclic voltammetry and differential pulse voltammograms (DPV). The modified electrode showed excellent electrocatalytic effect and high stability toward the electrochemical oxidation of dopamine (DA) in phosphate buffer solution The anodic peak currents increased linearly with the concentration of DA in the range of 5.0×10?7 to 1.0×10?4 M with a detection limit of 1.0×10?8 M (S/N = 3). Also, it showed a high stability for the determination of uric acid (UA) even in the presence of high concentration of DA. And the important is that the modified electrode could be used for the determination of DA in the presence of an ascorbic acid concentration as large as 100-fold that of DA. The proposed method was used to determine DA in DA-hydrochloride injection and showed excellent sensitivity and recovery. The results showed that these modified electrode has good stability and molecular recognization.Thirdly, we have successfully preparated NdHCF/Fe3O4 composite modified electrode. The composite were investied by using transmission electron microscopy (TEM), UV-vis spectroscopy, infrared spectroscopy (FTIR) and electrochemical. The modified electrode exhibited enhanced electrocatalytic behavior and good stability for the detection of H2O2. Under optimum conditions linear calibration graphs were obtained over the H2O2 concentration range 1.0×10-4-1.0×10-2 mol/L. The results showed that this modified electrode has good stability and high sensitivity.

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