Multiwall Carbon Nanotubes Modified Carbon Paste Electrode for Determination of Copper(II) by Potentiometric and Impedimetric Methods
نویسندگان
1 Department of Chemistry, Faculty of Science, Yazd University, Yazd, I. R. Iran
2 Department of Chemistry, Payame Noor University, P.O. Box 19395-4697 Tehran, I. R. Iran
3 Department of Analytical Chemistry, Faculty of Chemistry, University of Kashan, Kashan, 87317, I.R. Iran
4 Department of Organic Chemistry, Faculty of Chemistry, University of Kashan, Kashan, I. R. Iran
doi
10.7508/jns.2012.03.008چکیده
A chemically modified carbon paste electrode with multiwall carbon nanotube (MWCNT) was prepared and used as a sensor for Cu2+ ion. The unique chemical and physical properties of CNT have paved the way to new and improved sensing devices. A central composite chemometrics design was applied for multivariate optimization of the effects of three significant parameters (Graphite powder (X1), MWCNT (X2) and Ionophre (X3)) influencing the response of the electrode. In the optimized conditions, the electrode exhibits a Nernstian slope of 30.1 mV/decade in a linear range between 1.0×10-6 to1.0×10-1 M over a wide pH range (2.0-6.5). Importantly, the effect of the MWCNT on the performance of electrode was investigated by impedance technique, that showed the MWCNT helps the transduction of the signal in carbon paste electrode and the charged transfer resistance (Rct) was reduced. The impedimetric results indicated that the linear concentrations range was 1.0×10−7 to 1.0×10−1 M and in comparison with potentiometry, the pH range increased to 2.0−7.5.
