Low-cost Pencil-Graphite Multi-electrodes for Simultaneous Detection of Iron and Copper

Abstract

Herein, two novel ion-selective electrodes are reported for simultaneous potentiometric determination of Fe3+ and Cu2+ ions. The liquid polymeric membrane components were optimized and the resulting pencil graphite electrodes gave Nernstian slopes of 20.7 mV/decade and 31.2 mV/decade with lower detection of limit of 1×10-6 mol L-1 and 2×10-6 mol L-1, and wide pH range of 1.5-3.5 and 2.0-4.7 for Fe3+ and Cu2+ ions, respectively. The electrodes exhibited very fast response time (<6 s). In addition, the electrodes exhibited high selectivity for Fe3+ and Cu2+ ions against different cations, which were tested by matched potential method. The sensing platform using the optimized electrodes were integrated with the Internet of Things concept are suitable for simultaneous monitoring of Fe3+ and Cu2+ in real samples with high accuracy and precision.