Fluoroquinolones (FQs) are widely used in livestock and poultry industry because of their satisfactory effects in preventing and treating bacterial infection. However, due to irrational use and poor biodegradability, FQs can easily remain in food animals and further enter the human body through the food chain. Therefore, accurate and sensitive detection of FQs residues in animal-origin food is significant. The traditional methods commonly used for FQs detection have some limitations. Ratiometric fluorescence detection technology has the advantages of fast, sensitive, self-correcting, and easy visualization. However, the reports on the use of ratiometric fluorescence probes for FQs detection are limited. In this work, a novel probe was proposed for ratiometric fluorescent analysis of FQs. In this probe, the fluorescence of dithioerythritol stabilized copper nanoclusters (DTE-Cu NCs) was significantly enhanced due to the Tb triggered aggregation-induced emission effect. FQs bound Tb in Tb/DTE-Cu NCs through carboxyl and carbonyl groups, so that Tb was effectively sensitized to emit green fluorescence. However, the red fluorescence of DTE-Cu NCs was not interfered. The fluorescence of the probe transformed from red to green with the increase of FQs concentration. Using norfloxacin (NOR), difloxacin (DIF), and enrofloxacin (ENR) as FQs simulants, this probe showed a sensitive linear response ranged from 0.025 to 22.5 μM, with the limits of detection of 9.6 nM, 9.3 nM, and 7.7 nM. The application potential for FQs detection was verified via a standard addition assay of egg samples with the recovery rate of 90.4 %–114.7 %. The fluorescence probe based on Tb/DTE-Cu NCs is expected to realize the ratiometric fluorescence sensitive detection of FQs. The establishment of this simple, effective, and rapid detection platform opens up a new way for the detection of FQs residues in animal-origin foods, and also provides a new idea for the design of rapid detection platforms for other hazard factors.

中文翻译：

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Tb3+ 辅助二硫赤藓糖醇稳定的具有 AIE 行为的铜纳米簇用于氟喹诺酮类药物的比率荧光测定


氟喹诺酮类药物(FQs)因其防治细菌感染的良好效果而广泛应用于畜禽养殖业。但由于使用不合理、生物降解性差，FQs很容易残留在食用动物体内，并通过食物链进一步进入人体。因此，准确、灵敏地检测动物源性食品中的FQs残留具有重要意义。常用的 FQ 检测的传统方法有一些局限性。比率荧光检测技术具有快速、灵敏、自校正、易于可视化等优点。然而，关于使用比率荧光探针进行FQs检测的报道有限。在这项工作中，提出了一种用于 FQ 比率荧光分析的新型探针。在该探针中，由于 Tb 触发的聚集诱导发射效应，二硫赤藓糖醇稳定的铜纳米簇 (DTE-Cu NCs) 的荧光显着增强。 FQs通过羧基和羰基结合Tb/DTE-Cu NCs中的Tb，从而有效地敏化Tb以发射绿色荧光。然而，DTE-Cu NCs 的红色荧光并未受到干扰。随着FQs浓度的增加，探针的荧光由红色转变为绿色。使用诺氟沙星 (NOR)、二氟沙星 (DIF) 和恩诺沙星 (ENR) 作为 FQ 模拟物，该探针表现出灵敏的线性响应范围为 0.025 至 22.5 μM，检测限为 9.6 nM、9.3 nM 和 7.7 nM。通过鸡蛋样品的加标分析验证了 FQs 检测的应用潜力，回收率为 90.4%–114.7%。基于Tb/DTE-Cu NCs的荧光探针有望实现FQs的比率荧光灵敏检测。 这一简单、有效、快速检测平台的建立，为动物源性食品中FQs残留检测开辟了一条新途径，也为其他危害因素快速检测平台的设计提供了新思路。