An Electrochemical Sensor Based on Novel Ion Imprinted Polymeric Nanoparticles for Selective Detection of Lead Ions

In this study, the novel surface ion-imprinted polymer (IIP) particles were prepared and applied as a electrode modifier in stripping voltammetric detection of lead(II) ion. A carbon paste electrode (CPE) modified with IIP nanoparticles and multi-walled carbon nanotubes (MWCNTs) was used for accumulation of toxic lead ions. Various factors that govern on electrochemical signals including carbon paste composition, pH of the preconcentration solution, supporting electrolyte, stirring time, reduction potential and time were studied in detail. The best electrochemical response for Pb(II) ions was obtained with a paste composition of 7% (w/w) of lead IIP, 10% MWCNTs, 53% (w/w) of graphite powder and 30% (w/w) of paraffin oil using a solution of 0.1 mol L-1 acetat buffer solution (pH=4.5) with a extraction time of 15 min. A sensitive response for Pb(II) ions in the concentration range of 3 to 55 µg L-1 was achived. The proposed electrochemical sensor showed low detection limit (0.5 µg L-1), remarkable selectivity and good reproducibility (RSD = 3.1%). Determination of lead(II) content in different environmental water samples was also realized adopting graphite furnace atomic absorptions spectrometry (GF-AAS) and the obtained results were satisfactory.