Copper(II) determination by using carbon paste electrode modified with molecularly imprinted polymer

Abstract

A high selective voltammetric sensor for Cu 2+ was introduced. Cu 2+ selective molecular imprinted polymers (MIPs) and non-imprinted polymers (NIPs) were synthesized and then used for carbon paste (CP) electrode preparation. The MIP, incorporated in the carbon paste electrode, functioned as selectively recognition element and pre-concentrator agent for Cu 2+ determination. The prepared electrode was used for Cu 2+ measurement by the three steps procedure, including analyte extraction in the electrode, electrode washing and electrochemical measurement of Cu 2+. The complete removal of Cu 2+ from polymer was confirmed by IR and EDX. The MIP-CP electrode showed very high recognition ability in comparison to NIP-CP. It was shown that electrode washing after Cu 2+ extraction led to enhanced selectivity. Some parameters affecting sensor response were optimized and then a calibration curve plotted. Two dynamic linear ranges of 7.0 × 10 −8 to 1 × 10 −6 mol/l and 1.0 × 10 −6 to 1 × 10 −4 mol/l were obtained. The detection limit of the sensor was calculated equal to 2.3 × 10 −8 mol/l. This sensor was used successfully for Cu 2+ determination in Yellow river water.