Significant applications of an affordable and simply prepared portable carbon‐based potentiometric sensor for the highly selective and sensitive determination of Cu(II) ions released from food contact materials.

Herein, an affordable, sensitive, and accurate potentiometric method based on a modified carbon paste electrode (MCPE) incorporating 2,2′‐(ethane‐1,2‐diylbis (sulfanediyl)) dianiline, as a selective ionophore, has been introduced for the determination of Cu(II) ions concentration in different real samples. The developed MCPE has a high sensitivity for Cu(II) ions within a wide concentration range from 1.0 × 10−7 to 5.0 × 10−3 mol L−1, a low limit of detection value (LOD) of 5.6 × 10−8 mol L−1, and a Nernstian slope of 29.4 ± 0.28 mV/decade. Furthermore, the developed sensor has a rapid response time (24 s), can work successfully in a wide pH range of 4.5–7.0, and is highly selective to Cu(II) ions over many other cations. The proposed sensor's external surface was scrutinized by the scanning electron microscope (SEM) and energy dispersive X‐ray analysis (EDX). Finally, the optimized MCPE was successfully applied for the determination of Cu(II) ions content in different soil samples. Moreover, our MCPE is the first potentiometric sensor applied for the monitoring of the release of Cu(II) ions from one of the commercially available unlined copperware after exposure to food simulants under different conditions. The results were in agreement with those of the inductively coupled plasma (ICP) technique. [ABSTRACT FROM AUTHOR]