Key Laboratory for Biorheological Science and Technology of Ministry of Education, State and Local Joint Engineering Laboratory for Vascular Implants, Bioengineering College of Chongqing University, Chongqing, 400044, PR China.
Key Laboratory of Eco-Environment of Three Gorges Region of Ministry of Education, Faculty of Urban Construction and Environmental Engineering, Chongqing University, Chongqing, 400045, PR China.
Anal Chim Acta. 2020 Apr 29;1108:152-159. doi: 10.1016/j.aca.2020.02.028. Epub 2020 Feb 20.
In this study, direct detection of fluazinam was realized using a fluorescent sensor using disulfide quantum dots (MoS QDs) via inner filter effect (IFE). The maximum excitation of as-prepared MoS QDs presented a complementary spectral-overlap with the maximum absorption of fluazinam. Thus the occurrence of inner filter effect led to the significant fluorescence quenching of MoS QDs. Additionally, fluorescent quenching efficiency of MoS QDs could be enhanced by the effects of π-π stacking, hydrogen bond and electrostatic interaction between fluazinam and MoS QDs, and these non-chemical bond responses also promoted the selectivity for fluazinam detection. Under the optimum conditions, the IFE-based fluorescent sensor exhibited a relative wide linear range from 50 nM to 25 μM with the LOD of 2.53 nM (S/N = 3). In addition, a paper-based sensor was established by cross-linking the MoS QDs into cellulose membrane for naked-eyed detection and digital analysis of fluazinam. The paper-based sensor presented a liner range from 10 μM to 800 μM for fluazinam detection with the LOD of 2.26 μM. Additionally, the acceptable recoveries were obtained for fluazinam detection in the spiked samples of tomato, potato and cucumber, indicating that the proposed method provided an effective sensing platform for real applications of fluazinam detection in food safety.
在这项研究中，通过内滤效应（IFE）使用二硫化钼量子点（MoS QDs）荧光传感器实现了氟唑菌酰胺的直接检测。所制备的 MoS QDs 的最大激发与氟唑菌酰胺的最大吸收呈现互补光谱重叠，因此内滤效应的发生导致 MoS QDs 的荧光显著猝灭。此外，氟唑菌酰胺和 MoS QDs 之间的π-π堆积、氢键和静电相互作用增强了 MoS QDs 的荧光猝灭效率，这些非化学键响应也促进了对氟唑菌酰胺检测的选择性。在最佳条件下，基于内滤效应的荧光传感器表现出从 50 nM 到 25 μM 的相对宽线性范围，LOD 为 2.53 nM（S/N = 3）。此外，通过将 MoS QDs 交联到纤维素膜中，建立了一种用于肉眼检测和氟唑菌酰胺数字化分析的纸质传感器。该纸质传感器对氟唑菌酰胺的检测呈现出从 10 μM 到 800 μM 的线性范围，LOD 为 2.26 μM。此外，在番茄、土豆和黄瓜的加标样品中，对氟唑菌酰胺的检测得到了可接受的回收率，表明该方法为食品安全中氟唑菌酰胺的实际检测提供了有效的传感平台。
