Highly sensitive chemiluminescent sensor for detecting o-toluenesulfonamide and sulfamethoxazole using Cu-doped carbon dots.

In this study, Cu doped carbon dots (Cu-CDs) of uniform particle size and good water solubility was synthesized using Angelica Sinensis Radix as precursor materials through a one-step hydrothermal. The Lucigenin-(Cu-CDs) chemiluminescence sensor allows the simultaneous determination of o-toluenesulfonamide (TFA) and sulfamethoxazole (STZ) concentrations. Under optimal conditions, the sensor demonstrates the capability to detect TFA and STZ within the ranges of 50 μM-800 μM and 15 μM-120 μM, respectively. The limits of detection (LOD) for TFA and STZ are determined as 0.09 μM and 0.05 μM, respectively. While the limits of quantification (LOQ) are established at 0.3 μM and 0.17 μM, respectively. The feasibility of the method for determining TFA and STZ content in chicken samples was substantiated, demonstrating spiked recovery rates ranging from 97.5% to 102.3 % and 97.5%-99.8 %, respectively. The possible reaction mechanism was clarified based on chemiluminescence, UV-vis measurement and free radical analysis results. The newly established system is characterized by stability, convenience, and robust anti-interference capabilities, thus expanding the application of carbon dots and offering a promising strategy for the detection of TFA and STZ.