Molecularly imprinted potentiometric sensor for surfactant based on electrosynthesized polyaniline

Abstract

A potentiometric sensor for sodium dodecylsulfate (SDS) was developed based on molecularly-imprinted polyaniline. The molecularly-imprinted polymer was synthesized through a potentiostatic electropolymerization of aniline monomer in the presence of the template SDS molecule at a constant potential of 0.8 V. The polymerization parameters determined the analytical performance of the polyaniline reagent phase. The optimized electropolymerization process provided a sensor with sensitivity of 45.546 mV/decade, working concentration range of 310 -6 M to 110 -2 M SDS, correlation coefficient (r 2 ) of 0.993 and with a limit of detection 110 -5 M DS -. The sensor response is reproducible with a mean RSD of 8.08% from 310 -6 M to 310 -3 M SDS. Selectivity studies using the fixed primary ion method proved the higher selectivity of the synthesized polymer for SDS over inorganic salts and fatty acid salts.