A New Hydroxylamine Electrochemical Sensor Based on an Oxadiazol Derivative and Multi-wall Carbon Nanotuhes Modified Glassy Carbon Electrode

A new hydroxylamine sensor has been fabricated by immobilizing oxadiazol denvative at the surface ol aglassy carbon electrode (GCE) modified by multi-wall carbon nanotube (MIVCNT). The adsorbed thin Illms oroxadiazol derivative on the MWCNT modified GCE show a pair of peaks with surface confined characierisnus.The oxadiazol derivative MWCNI (OMWCNT) modified GCE shows highly catalytic activity togurdelectrooxidation of hydroxylamine. The results show that the peak potential of hydroxylamine at OMWCNTmodified GCE surface shifted by about 331 and 346 my toward nevative values compared with those orMIVCNT and activated OCE surface. respectively. In addition. the sensitivity of hydroxylamine determinationis improved remarkably by OMWCNT modified electrode. The kinetic parameters, such as the electron transfercoefficient, a. the standard heterogencouq rate constant, kg and exchange current. i0, for oxidation orhydroxylamtne at the OMWCNT modified GCE (041WCH1-GCE) were determined by cyclic voltainmcirymeasurements. Also &fusion coefficient of hydroxylamine was determined as 4.05 g l0 ctn2 s I by usiagchronoamperometry technique. Furthermore, the linear dynamic range (2 0-600.0 pM), sensitivity and detectionlimit (0.61 pM) for hydroxylamine determination was evaluated using differential pulse voltammary. Excellentelectrochemical reverkibility of the redox couple. technical simplicity, good electrocatalytic activity forhydros ylamine and good reproducibility are the advantages of this modified electrode. ginally. the activi” ofOAIWCNT-UCE ...as also investigated for hydroxylamine determinatm on in two natural water samples.