Selective voltammetric determination of Cu(II) based on multiwalled carbon nanotube and nano-porous Cu-ion imprinted polymer

A very high selective Cu-ion imprinted polymer as a chemical modifier was prepared by formation of 1-(2-pyridylazo)-2-naphthol complex for stripping voltammetric determination of copper. Polymerization was performed with ethylene glycol dimethacrylate, as crosslinking monomer and methacrylic acid as functional monomer; in the presence of 2,2′-azobis(isobutyronitrile), as initiator, via bulk polymerization. The electrochemical method is based on accumulation of copper ions at −0.6 V on the surface of Cu-IIP–CNT-modified carbon paste electrode. After preconcentration, the measurements were carried out in a closed circuit by electrolysis of the accumulated Cu(II) by voltammetric scanning from −0.25 to +0.1 V. Under optimized conditions, a linear response range from 2 to 120 μg L−1 was obtained. The detection limit of Cu(II) was 0.34 μg L−1 and RSD for 50.0 μg L−1 was ±2.4%. The modified electrode showed high selectivity, sensitivity and stability and was applied for enrichment and electrochemical detection of ultra trace copper ion in real samples.

Graphical abstract(a) Preparation of Cu(II)-IIP, (b) Preparation of Cu-IIP–CNT–MCPE, (c) Accumulation and differential pulse anodic stripping voltammetry and (d) Voltammogram.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► A high selective nano-porous Cu-IIP was prepared for voltammetric determination of Cu. ► Use of carbon nanotube with ionic imprinting technology increases the sensitivity. ► The procedure is simple, rapid, green, effective and selective. ► The method can be used for ultra trace determination of Cu in wide range of samples.