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 mu g L-1 was obtained. The detection limit of Cu(II) was 0.34 mu g L-1 and RSD for 50.0 mu g 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. (C) 2012 Elsevier B.V. All rights reserved.