A Novel Electrochemical Nanosensor for the Simultaneous Sensing of Two Toxic Food Dyes

This work reports for the first time the preparation and performance of a nanosensor for the simultaneous detection of metanil yellow and fast green, which are toxic food dyes. For the development of this sensitive platform, the surface of a glassy carbon electrode (GCE) was modified with calixarene and gold nanoparticles. The sensing ability of the designed nanosensor (calix8/Au NPs/GCE) was tested by cyclic voltammetry, differential pulse voltammetry, and electrochemical impedance spectroscopy. The influence of a number of parameters was investigated for optimizing the conditions to achieve the best response of the target analytes. Due to the synergistic activity of calix[8]arene and Au nanoparticles, the calix8/Au NPs/GCE nanocomposite was found to significantly enhance the signals of the selected food dyes in comparison to bare GCE. Under optimized conditions, limits of detection for metanil yellow and fast green were found to be 9.8 and 19.7 nM, respectively, at the calix8/Au NPs/GCE. The designed sensing platform also demonstrated figures of merit when applied for the sensing of food dyes in real water and juice samples. Moreover, high percent recovery, reproducibility, and stability suggested applicability of the designed electrochemical platform for real sample analysis.