Modified Carbon Paste Electrode Based on Multi-Walled Carbon Nanotubes (MWCNTs) and Ionic Liquid for Potentiometric Determination of Cu²⁺ Ions in Real Samples

Carbon paste electrode based on multi-wall carbon nanotube (MWCNT) and ionic liquid was prepared and used for the potentiometric determination of copper ion. A multi-walled carbon nanotubes (MWCNTs) was used in the composition of the carbon paste to enhance conductivity and transduction of chemical signal to electrical signal. Furthermore, unification of 1,4-diamino anthraquinone as an ionophore to this composition caused to significantly improve d selectivity toward Cu (II) ions. The electrode show a nernstian slope of 29.5 ±0.2 mV per decade for Cu ion over a wide concentration range from 1.0×10 to 1.0×10 M.The lower detection limits is 8.0×10 -7 M. The electrode has a fast response time (<5 s), a satisfactory relatively long life time and reproducibility. The proposed sensor revealed a fairly good selectivity toward Cu ion in comparison to other common cations and the working pH range was 3.0-12. In a final manner, these electrode have been successfully implemented for the determination of Cu ions content in real samples.