Wang Xiaohui, Liu Chang, Cao Yichuan, Cai Lin, Wang Haiyang, Fang Guozhen
State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science and Technology, Tianjin 300457, China.
School of Food Science, Henan Institute of Science and Technology, Xinxiang 453003, China.
Foods. 2023 Jun 3;12(11):2255. doi: 10.3390/foods12112255.
Developing sensitive and effective methods to monitor oxytetracycline residues in food is of great significance for maintaining public health. Herein, a fluorescent sensor (NH-UIO-66 (Zr)@MIP) based on a molecularly imprinted polymer-coated amino-functionalized zirconium (IV) metal-organic framework was successfully constructed and first used for the ultrasensitive determination of oxytetracycline. NH-UIO-66 (Zr), with a maximum emission wavelength of 455 nm under 350 nm excitation, was prepared using a microwave-assisted heating method. The NH-UIO-66 (Zr)@MIP sensor with specific recognition sites for oxytetracycline was then acquired by modifying a molecularly imprinted polymer on the surface of NH-UIO-66 (Zr). The introduction of NH-UIO-66 (Zr) as both a signal tag and supporter can strengthen the sensitivity of the fluorescence sensor. Thanks to the combination of the unique characteristics of the molecularly imprinted polymer and NH-UIO-66 (Zr), the prepared sensor not only exhibited a sensitive fluorescence response, specific identification capabilities and a high selectivity for oxytetracycline, but also showed good fluorescence stability, satisfactory precision and reproducibility. The fabricated sensor displayed a fluorescent linear quenching in the OTC concentration range of 0.05-40 μg mL, with a detection limit of 0.012 μg mL. More importantly, the fluorescence sensor was finally applied for the detection of oxytetracycline in milk, and the results were comparable to those obtained using the HPLC approach. Hence, the NH-UIO-66 (Zr)@MIP sensor possesses great application potential for the accurate evaluation of trace oxytetracycline in dairy products.
开发灵敏有效的食品中土霉素残留监测方法对维护公众健康具有重要意义。在此，基于分子印迹聚合物包覆的氨基功能化锆（IV）金属有机框架成功构建了一种荧光传感器（NH-UIO-66（Zr）@MIP），并首次用于土霉素的超灵敏测定。采用微波辅助加热法制备了在350 nm激发下最大发射波长为455 nm的NH-UIO-66（Zr）。然后通过在NH-UIO-66（Zr）表面修饰分子印迹聚合物获得了对土霉素具有特异性识别位点的NH-UIO-66（Zr）@MIP传感器。引入NH-UIO-66（Zr）作为信号标签和载体可增强荧光传感器的灵敏度。由于分子印迹聚合物和NH-UIO-66（Zr）的独特特性相结合，所制备的传感器不仅对土霉素表现出灵敏的荧光响应、特异性识别能力和高选择性，而且还具有良好的荧光稳定性、令人满意的精密度和重现性。所制备的传感器在土霉素浓度范围为0.05 - 40 μg mL时呈现荧光线性猝灭，检测限为0.012 μg mL。更重要的是，该荧光传感器最终应用于牛奶中土霉素的检测，结果与采用高效液相色谱法获得的结果相当。因此，NH-UIO-66（Zr）@MIP传感器在准确评估乳制品中痕量土霉素方面具有巨大的应用潜力。
