Rapid electrochemical synthesis of molecularly imprinted polymers on functionalized multi-walled carbon nanotubes for selective recognition of sunset yellow in food samples

Abstract

The monitoring of synthetic colorants in foods is very important due to their potential toxicity and pathogenicity. Therefore, we proposed a new and facile electrochemical method for the determination of sunset yellow (SY) in food samples. A highly sensitive and selective electrochemical sensor was fabricated by electropolymerization of molecularly imprinted polymer (MIP) in the presence of SY onto a functionalized multi-walled carbon nanotubes/glassy carbon electrode (f-MWCNTs/GCE) using cyclic voltammetry (CV). Scanning electron microscopy and CV were employed to characterize the fabricated sensor. The experimental parameters, such as supporting electrolyte and its pH, the monomer concentration, the number of cycles for the electropolymerization and the scan rate for the sensor preparation were optimized. The MIP sensor exhibited an excellent recognition capacity toward SY compared with other structurally similar molecules. Under the optimum operating conditions, the current response of the MIP sensor was linear to SY concentrations in the range from 0.05 to 100μM, with the detection limit of 5.0nM. Finally, the proposed electrode was successfully applied to determine SY in several food samples.