Rapid potentiometric sensor for determination of Cu(II) ions in food samples

•Copper is an essential trace element with great importance for living organisms.•Developing selective and sensitive sensors for Cu(II) ions is of great importance.•This paper reports a new highly selective and sensitive Cu(II) ions-MCPE.•Our MCPE showed a Nernstian slope of 29.9±0.15 mV decade−1 over a wide linear range.•The proposed electrode showed a fast response time of 6 s.•Our MCPE was applied successfully for Cu(II) ions determination in food samples.•The electrode surfaces were characterized using EDX and SEM techniques. Copper is considered as one of the first metals used by humans. It is an essential trace element with great significance in the normal functioning and keeping of a large number of body systems. Developing selective, sensitive, and easily prepared sensors for the measurement of Cu(II) ions in different matrices is critical. This paper reports a new highly selective and sensitive Cu(II) ions modified carbon paste electrode (MCPE) based on 2-(3-phenoxy phenyl) propanoic acid (Fenoprofen (FP)) as a Cu(II) selective modifier. The developed MCPE exhibits a Nernstian slope of 29.9 ± 0.15 mV decade−1 in the linear range of 1.0 × 10−6 to 1.0 × 10−2 mol L−1 with a rapid response time of 6 s and pH-independency in the range of 3.0–5.0. The proposed MCPE showed a negligible change in the slope or the working range when the measurement was applied in a partially non-aqueous medium and showed high selectivity toward Cu(II) ions in comparison with numerous other cations. The applicability of the proposed MCPE for Cu(II) ions determination in various food samples was also examined. Furthermore, the morphology of the proposed MCPE surface was investigated using energy-dispersive X-ray (EDX) and scanning electron microscopic (SEM) to confirm the interaction between Cu(II) ions and FP.