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, Sichuan, 644004, China.
School of Food and Biological Engineering, Xihua University, Chengdu, 610039, China.
Talanta. 2021 Dec 1;235:122783. doi: 10.1016/j.talanta.2021.122783. Epub 2021 Aug 4.
As the light-harvesting "antenna", G-rich oligonucleotides (such as the G-quadruplex) can interact with lanthanide (III) to bring a luminescent enhancement response. In this study, phenomenon of luminescent enhancement of G-triplex/terbium (III) (G3/Tb) and interaction between G3 and Tb were first reported and characterized. Based on G3/Tb luminescence, a label-free aptasensor for the detection of ofloxacin (OFL) residues in the food was developed. The OFL triggered the action of rolling circle amplification (RCA) allowed for the amplification product of G3-forming sequences in the single-stranded DNA, which promoted the conformational transition of the G3/Tb complexes once the addition of Tb. Under the optimal conditions, the logarithmic correlation between the G3/Tb luminescence intensity and the concentration of OFL was found to be linear in the range of 5-1000 pmol L (R = 0.9949). The limit of detection was 0.18 pmol L (3σ/slope). Additionally, the good recoveries of 90.19-108.89 % and the relative standard deviations values of 0.59-5.87 % were obtained in the application of the aptasensor detecting OFL in the practical samples. These results confirmed that the present aptasensor has a good analytical performance and bright prospect for detecting ofloxacin residues in food.
作为光收集“天线”，富含鸟嘌呤的寡核苷酸（如 G-四链体）可以与镧系元素（III）相互作用，带来发光增强响应。在这项研究中，首次报道并表征了 G-三聚体/铽（III）（G3/Tb）的发光增强现象和 G3 与 Tb 之间的相互作用。基于 G3/Tb 的发光，开发了一种用于检测食品中氧氟沙星（OFL）残留的无标记适体传感器。OFL 触发滚环扩增（RCA）的作用，允许单链 DNA 中 G3 形成序列的扩增产物，一旦加入 Tb，就会促进 G3/Tb 配合物的构象转变。在最佳条件下，发现 G3/Tb 发光强度与 OFL 浓度之间存在对数相关性，在 5-1000 pmol L（R=0.9949）范围内呈线性关系。检测限为 0.18 pmol L（3σ/斜率）。此外，在实际样品中检测 OFL 时，适体传感器的回收率为 90.19-108.89%，相对标准偏差值为 0.59-5.87%，结果表明该适体传感器具有良好的分析性能，在检测食品中的氧氟沙星残留方面具有广阔的前景。
