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

Document Type : Research Paper




A new hydroxylamine sensor has been fabricated by immobilizing oxadiazol denvative at the surface ol a
glassy carbon electrode (GCE) modified by multi-wall carbon nanotube (MIVCNT). The adsorbed thin Illms or
oxadiazol 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 togurd
electrooxidation of hydroxylamine. The results show that the peak potential of hydroxylamine at OMWCNT
modified GCE surface shifted by about 331 and 346 my toward nevative values compared with those or
MIVCNT and activated OCE surface. respectively. In addition. the sensitivity of hydroxylamine determination
is improved remarkably by OMWCNT modified electrode. The kinetic parameters, such as the electron transfer
coefficient, a. the standard heterogencouq rate constant, kg and exchange current. i0, for oxidation or
hydroxylamtne at the OMWCNT modified GCE (041WCH1-GCE) were determined by cyclic voltainmciry
measurements. Also &fusion coefficient of hydroxylamine was determined as 4.05 g l0 ctn2 s I by usiag
chronoamperometry technique. Furthermore, the linear dynamic range (2 0-600.0 pM), sensitivity and detection
limit (0.61 pM) for hydroxylamine determination was evaluated using differential pulse voltammary. Excellent
electrochemical reverkibility of the redox couple. technical simplicity, good electrocatalytic activity for
hydros ylamine and good reproducibility are the advantages of this modified electrode. ginally. the activi” of
OAIWCNT-UCE ...as also investigated for hydroxylamine determinatm on in two natural water samples.