Solid-state electrochemiluminescence sensor of luminol based on polymer donor PM6 and ZIF-8 for sensitive detection of sunset yellow in sports drinks

PM6 is a polymer donor characterized by a wide bandgap, commonly utilized in high-performance polymer solar cells. In this study, we applied PM6 to the field of electrochemiluminescence for the first time. By sequentially modifying PM6, CS@luminol and ZIF-8 on the electrode, we constructed a simple yet novel electrochemiluminescence (ECL) sensor for the detection of the colorant sunset yellow (SY). As a donor, PM6 enhanced the charge transfer rate within the system and improved its luminescence performance. CS served to stabilize the luminescent reagent due to its viscosity. ZIF-8 acted as an accelerator in the luminol luminescence system, facilitating the absorption of more active oxygen and generating additional reactive species on the electrode surface. The combined action of PM6 and ZIF-8 resulted in a luminol ECL sensor that exhibited a sensitive and stable signal. When exposed to sunset yellow, the ECL signal diminished consistently with increasing concentrations of SY. Under optimal conditions, the ECL attenuation signal demonstrated a linear relationship with the logarithm of SY concentration, with a linear range of 5.0 × 10 − 13 –5.0 × 10 − 8  mol L -1 , and a detection limit of 1.67 × 10 −13  mol L -1 (S/N = 3). The constructed sensor exhibited excellent stability, selectivity, and repeatability, making it suitable for the actual detection of sunset yellow in sports drinks.