Preparation of nano-sized Pb 2+ imprinted polymer and its application as the chemical interface of an electrochemical sensor for toxic lead determination in different real samples

Abstract

In this work, a new nano-structured ion imprinted polymer (IIP) was synthesized by copolymerization of methacrylic acid–Pb 2+ complex and ethylene glycol dimethacrylate according to the precipitation polymerization. Methacrylic acid acted as both functional monomer and complexing agent to create selective coordination sites in a cross-linked polymer. A carbon paste electrode modified with IIP-nanoparticles was used for fabrication of a Pb 2+ sensitive electrode. Differential pulse stripping voltammetry method was applied as the determination technique, after open circuit sorption of Pb 2+ on the electrode and its reduction to metallic form. The IIP modified electrode showed a considerably higher response, compared to the electrode embedded with non-imprinted polymer (NIP). This indicated that the suitable recognition sites were created in the IIP structure in the polymerization stage. Various factors, effective on the response behavior of the electrode, were investigated and optimized. The introduced sensor showed a linear range of 1.0 × 10 −9 to 8.1 × 10 −7 M and detection limit of 6.0 × 10 −10 M (S/N = 3). The sensor was successfully applied for the trace lead determination in different samples.