Thick film voltammetric sensors for trace copper based on a cation-exchanger-modified surface

Strip-type, preconcentrating/voltammetric sensors, prepared by incorporating a cation-exchange resin within screen-printed carbon inks, are described. Such single-use strips combine the efficient electrostatic accumulation of heavy metals with the use of "mercury-free" surfaces. The uptake of copper(II) from dilute solutions (under open circuit conditions) is followed by voltammetric measurements in a separate blank solution. Various experimental variables have been optimized to yield low detection limits (e.g. 0.5 mug 1(-1) with 10 min accumulation) and good reproducibility (relative standard deviation, 2%). The applicability to assays of drinking water is demonstrated.