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Abstract
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In this study, multi-wall carbon nanotube (MWCT) is evaluated as transducer, stabilizer and immobilization matrix for the construction of amperometric sensor based on immobilization of Iron porphyrin onto Glassy carbon electrode modified with multi wall carbon nanotube. The electrochemical response of the modified electrode in 0.1 M phosphate buffer solution indicated a well defined and nearly reversible redox couple was stabilized at the surface of electrode. Cyclic voltammetry of the electrode in PBS pH 2 shows the excellent elecreocatalytic activity toward reduction of ClO3-, BrO3- and IO3- at reduced overpotential. Optimum pH values for anions detection is 2 and catalytic rate constants are in range 2.4×103 -8.9×103 M-1s-1. The hydrodynamic amperometry at rotating modified electrode at constant potential used for detection of selected anions. The advantageous of the modified electrode are good stability, linear calibration range, high sensitivity, short response time and low detection limit; furthermore the method of sensor fabrication is simple, fast and reproducible.
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