Comparison of the influence of nanomaterials on response properties of copper selective electrodes

Novel Cu2+ ion selective electrode in carbon paste matrices based on incorporation of bis(2-hydroxynaphthaldehydene)-1,6-hexanediamine (BHNHDA) has been developed. The influence of variables including sodium tetraphenylborate (NaTPB), ionophore, and amount of multiwalled carbon nanotubes (MWCNT) and Nujol and effect of two new nanoparticles including gold nanoparticles loaded on activated carbon (Au-NP-AC) and zinc sulfide nanoparticles loaded on activated carbon (ZnS-NP-AC) on the electrodes response was studied and optimized. At optimum specified conditions, the proposed electrodes have appropriate advantages such as short response times and suitable reproducibility and applicability for a period of at least 1 month without any significant divergence in slope and response properties. The sensor based on impregnations of MWCNT, Au-NP-AC and ZnS-NP-AC have wide linear range of concentration (6 × 10−8–1.0 × 10−1 mol L−1) and detection limit of lower than 4 × 10−8 mol L−1 of Cu2+ ion. The electrodes based on incorporation of Au-NP-AC and ZnS-NP-AC have Nernstian response with slope of 29.34 ± 1.41 and 29.78 ± 1.23 mV decade−1 and response is independent of pH in the range of 2.0–5.0. Finally, these electrodes have been successfully applied for the determination of Cu2+ ions content in various real samples. Due to their acceptable selectivity coefficient, they are usable for accurate and successful evaluation of Cu2+ ions content in various real sample with complicated matrices.