Triazine-based COF/CNTs as an electrochemical sensor for the simultaneous detection of sunset yellow and tartrazine in food samples

In this study, we developed a novel electrochemical sensor by modifying a screen-printed carbon electrode (SPCE) with a triazine-based covalent organic framework (COF) and carbon nanotubes (CNTs), designated as the COF/CNTs/SPCE. This sensor enabled the simultaneous detection of sunset yellow (SY) and tartrazine (Tz) with excellent sensitivity. Under optimized conditions, the COF/CNTs/SPCE exhibited efficient electron-transfer kinetics and achieved low detection limits (S/N = 3) of 0.75 nM for SY and 7.5 nM for Tz, outperforming previously reported electrochemical sensors. The sensor demonstrated high selectivity for SY and Tz even in the presence of various common interferents, along with good reproducibility and long-term stability. Moreover, the COF/CNTs/SPCE sensor was successfully applied for the quantitative analysis of multiple food samples, validating its practical applicability. These results underscore the potential of the COF/CNTs/SPCE as a high-performance, reliable platform for detecting synthetic food dyes in complex food matrices.