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

Abstract

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 Cu2+ ion over a wide concentration range from 1.0×10-1
to 1.0×10-6 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 Cu2+ 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 Cu2+ ions content in real samples.