Determination of the azo dye, sunset yellow, using carbon paste electrode modified with molecularly imprinted polymer

Abstract

A highly selective voltammetric sensor for sunset yellow is reported. Sunset yellow selective molecular imprinted polymers (MIP) and non-imprinted polymers have been synthesized and used for preparation of carbon paste electrode. The MIP, incorporated in the carbon paste electrode, functions as selective recognition element and pre-concentrator agent for determination of the dye. The sensitivity of the sensor is improved greatly because of the multiwalled carbon nanotubes (MWCNTs). The complete removal of the dye from the polymer was confirmed by the infrared spectra and the differential pulse voltammetry. The MWCNTs/MIP/CPE has been characterized by electrochemical impedance spectroscopy, cyclic voltammetry and DPV. The MWCNTs/MIP/CPE shows very high recognition ability in comparison to the MWCNTs/NIP/CPE. Under the optimum conditions, the linear relationship between current and concentration was obtained in the range from 8×10^-8 to 1×10^-5mol L^-1. The detection limit of the sensor is 2.667×10^-8mol L^-1(S/N=3).