Abstract

Self-cross linked poly(4,4′-diaminodiphenylmethane) was prepared by an oxidative polymerization. Also a molecular imprinted polymer was prepared by employing 4,4′-diaminodiphenylmethane as the functional monomer, ammonium persulfate and dibenzothiophene as the oxidizing agent and template, respectively. It is suggested that the π–π stacking effect between 4,4′-methylenedianiline and dibenzothiophene induced the compact imprinted polymer and the formation of more imprinted sites. Field emission scanning electron microscopy, X-ray diffraction, differential scanning calorimetry and FTIR spectroscopy were used for the characterization of the synthesized polymers. The removal of template molecules leads to the preparation of molecularly imprinted polymer (MIP), which was subsequently used as an electrode material for the preparation of an electrochemical sensor for the detection of dibenzothiophene. Electrochemical behavior of dibenzothiophene on the sensors' construction based upon the application of imprinted (MIP) and non-imprinted (NIP) polymers was investigated in 0.1 mol L−1 of LiClO4 (as the supporting electrolyte), by means of cyclic voltammetry. The obtained cyclic voltammograms of the MIP electrode showed one irreversible anodic peak at ~ 1.5 V. This peak was attributed to the electrochemical oxidation of dibenzothiophene to dibenzothiophene sulfoxide. The current variation acquired through the developed imprinted sensors as a function of dibenzothiophene concentration was linear in the concentration range of 60–150 mg L−1. The corresponding limit of detection was calculated as 11 mg L−1. The imprinted sensor showed a significantly improved sensitivity towards the investigated analyte rather than that observed using a non-imprinted polymer.