Molecularly imprinted conducting polymer for determination of a condensed lignin marker

[Display omitted] •An electrochemical sensors for detection of condensed lignin is developed.•The sensor is based on a molecularly imprinted conducting polymer (MICP).•The MICP is prepared by electropolymerization in presence of a template molecule representing condensed lignin.•Binding of the template molecule was verified by molecular modeling.•The MICP responds to the template molecule at micromolar concentration. Condensed lignin is an undesired byproduct that has detrimental effects in cellulose pulping processes, increasing the consumption of bleaching chemicals and altering the properties of main products. A simple method for quantification of condensed lignin could greatly improve the performance and economy of pulping mills. In this work, a chemical sensing material based on a molecularly imprinted conducting polymer was synthesized by using a marker of condensed lignin as template molecule. Molecular modeling was used as an essential tool to understand and optimize the complexation of the functional monomers with the template in order to improve the synthesis strategy. The imprinted polymer was synthesized by co-electropolymerization of 3,4-ethylenedioxythiophene (EDOT) and 3-acetic acid thiophene (AAT) in presence of 2,2’-methylenebis(2-methoxy-4-methylphenol) as template, and studied by cyclic voltammetry and electrochemical impedance spectroscopy. The anodic peak current at +0.88 V (vs. Ag/AgCl/KCl 3 M) in the cyclic voltammograms of the imprinted polymer sensor was used to detect the lignin marker dissolved in pure solvents at concentrations ranging from 1 × 10−6 to 1 × 10−2 M.