Advanced Fluorometric Detection of Sulfathiazole Antibiotics in Food Samples with Molecularly Imprinted Polymer Coated CdTe Quantum Dots

Sulfathiazole (STZ) is an antibiotic used for bacterial infections in humans and to boost farm animal health. Overuse can lead to harmful antibiotic residues in meat, posing risks to human health. This also contributes to the rise of antibiotic-resistant bacteria. Here we developed a fluorescent sensor for the detection and monitoring of sulfathiazole, utilizing molecularly imprinted polymers (MIPs) that possess selective cavities tailored to the target analyte. These MIPs were integrated with quantum dotsnanocrystalline semiconductors known for their fluorescent propertiesresulting in a core@shell structure, referred to as QD@MIP. The synthesized materials were examined using a combination of advanced imaging and spectroscopic analysis method. Fluorescence analysis was used to optimize the acidity level and contact duration for QD@MIPs with STZ. With the conditions optimized, the sensor attained a linear detection range of 10 to 60 μg kg<sup>-1</sup>, establishing limit of detection value of 0.59 and 1.79 μg kg<sup>-1</sup> for limit of quantification, respectively. The QD@MIP was tested for repeatability and reliability, showing relative standard deviation (RSD) values under 9%. Tests with four potential interfering substances confirmed the high specificity of the sensor, which also demonstrated effectiveness in real animal-derived food samples, achieving recovery rates above 80% for fortified STZ. This study demonstrates the potential of the QD@MIP sensor for accurate and reliable monitoring and analysis of food samples, showcasing its excellent performance and quality.