Potentiometric Sensor Based on Layered Pillar[6]arene—Copper Composite

Abstract

A solid-contact potentiometric sensor has been developed on the basis of glassy carbon electrode covered with electropolymerized polyaniline and alternatively layered pillar[6]arene and Cu2+ ions films. The assembly of the surface layer was confirmed by surface plasmon resonance measurements. The number of deposited layers was selected to reach better analytical characteristics for Cu2+ determination. It was shown that better results were achieved by using five layers, the upper one consisting of the macrocycle. The addition of covering layers for polyelectrolytes (Nafion, poly(styrene sulfonate)) and Cu2+ ions did not improve sensor performance. The potentiometric sensor made it possible to determine Cu2+ ions in neutral and weakly acidic media with a linear range of the concentrations, from 3.0 μM to 10.0 mM (limit of detection 3.0 μM). The applicability of the sensor in real sample assays was confirmed by the determination of Cu2+ ions in copper vitriol, Bordeaux mixture, and polyvitamin-mineral pills of “Complivit” during an atomic emission spectroscopy analysis.