College of Chemistry and Chemical Engineering, Henan Polytechnic University, No. 2001 Shiji Road Jiaozuo, Henan 454000, China.
College of Chemistry and Chemical Engineering, Henan Polytechnic University, No. 2001 Shiji Road Jiaozuo, Henan 454000, China.
J Hazard Mater. 2021 May 5;409:124935. doi: 10.1016/j.jhazmat.2020.124935. Epub 2021 Jan 8.
Ultrasensitive and visual detection of tetracycline antibiotic (TC) residues is of great significance to public health and environmental safety. A novel dual-response ratiometric fluorescent nano-probe (SiQDs-Cit-Eu) has been elaborately tailored for the determination and on-site visual assay of tetracycline, by grafting citric acid and europium (Eu) ions onto the surface of silicon quantum dots (SiQDs). The blue-emissive SiQDs (λ = 455 nm) fabricated by a one-step facile method act as both scaffold for coordination with Eu ions and recognition unit for TC owing to the inner filter effect (IFE). The coordinate unsaturated red-fluorescent Eu ions (λ = 617 nm) bond to the surface of SiQDs, serving as the specific recognition element for TC due to the antenna effect. In the presence of TC, the as-synthesized nano-probe exhibits double (λ = 455 and 617 nm) and reverse response signals which are accompanied by a marked color change from blue to purple, and then red, thus achieving ultra-high sensitivity with a detection limit of 7.1 nM and instant visual detection of TC in real samples (milk, honey, lake and river water). Furthermore, smartphone-assisted point-of-care testing platform is also constructed based on nano-probe-immobilized test paper by using the color scanning APP.
超灵敏和可视化检测四环素抗生素 (TC) 残留对于公共卫生和环境安全具有重要意义。本研究设计了一种新颖的双响应比率荧光纳米探针 (SiQDs-Cit-Eu)，通过将柠檬酸和铕 (Eu) 离子接枝到硅量子点 (SiQDs) 的表面，用于四环素的测定和现场可视化分析。通过一步简便的方法制备的蓝色发射 SiQDs（λ = 455nm）既作为与 Eu 离子配位的支架，也作为 TC 的识别单元，这归因于内滤效应 (IFE)。配位不饱和的红色荧光 Eu 离子（λ = 617nm）键合到 SiQDs 的表面，由于天线效应，其作为 TC 的特定识别元素。在 TC 存在下，所合成的纳米探针表现出双重（λ = 455 和 617nm）和反向响应信号，同时伴有从蓝色到紫色，然后到红色的明显颜色变化，从而实现了超灵敏检测，检测限低至 7.1nM，并可即时可视化检测实际样品（牛奶、蜂蜜、湖水和河水）中的 TC。此外，还通过使用颜色扫描 APP，构建了基于纳米探针固定化试纸的智能手机辅助即时检测平台。
