School of Food and Biological Engineering, Xihua University, Chengdu, 610039, China.
Key Laboratory of Food Non-Thermal Processing, Engineering Technology Research Center of Food Non-Thermal Processing, Yibin Xihua University Research Institute, Yibin, 644004, China.
Anal Bioanal Chem. 2020 Jul;412(19):4555-4563. doi: 10.1007/s00216-020-02708-3. Epub 2020 May 29.
A novel sensitive, competitive, and time-resolved luminescence sensor for the detection of ofloxacin (OFL) was developed in this study. The sensor used OFL-specific aptamer as a recognition molecule and rolling circle amplification (RCA) as a signal amplification tool. In this way, the time-resolved luminescence can not only avoid background noise from sample, but also provide robust luminescence for detection. Besides, the separation and enrichment of target veterinary drug can be conducted assisted by magnetic treatment. Under optimal conditions, the logarithmic correlation between the concentration of OFL and the luminescence intensity was found to be linear in the range of 5 × 10-5 × 10 mol L (R = 0.9988), with a detection limit (LOD) of 32.1 pmol L. Furthermore, this method was applied to the determination of OFL in chicken and pork samples, exhibiting good recovery (72.5-100%) and repeatability (RSD < 10.0%). These results confirm that this novel established method has good application potential for the detection of OFL in food samples.
本研究开发了一种用于检测氧氟沙星（OFL）的新型灵敏、竞争性和时间分辨荧光传感器。该传感器使用 OFL 特异性适体作为识别分子，并采用滚环扩增（RCA）作为信号放大工具。这样，时间分辨荧光不仅可以避免来自样品的背景噪声，还可以为检测提供稳健的荧光。此外，还可以通过磁处理辅助进行目标兽药的分离和富集。在最佳条件下，OFL 浓度与荧光强度之间的对数相关性在 5 × 10-5 × 10 mol L 的范围内呈线性关系（R = 0.9988），检测限（LOD）为 32.1 pmol L。此外，该方法还应用于鸡肉和猪肉样品中 OFL 的测定，表现出良好的回收率（72.5-100%）和重复性（RSD < 10.0%）。这些结果证实，该新型建立的方法在食品样品中检测 OFL 具有良好的应用潜力。
