啶虫脒(ACE)是一种高效的广谱杀虫剂,它的广泛使用对人类健康和环境安全有潜在的危害。在这项研究中,磁性Fe3O4/碳(Fe3O4/C),金属有机骨架MIL-101(Fe)的衍生物,通过两步煅烧法合成。并开发了一种荧光传感策略,用于使用Fe3O4/C和多个互补单链DNA(ssDNA)高效,灵敏地检测ACE。通过使用具有多个互补ssDNA的适体,提高了aptasensor的抗干扰能力,适应量具有较高的选择性和灵敏度。当ACE出现时,适体(Apt)结合ACE。Apt的互补链(Cs1)与Cs1的两条短互补链、荧光团6-羧基荧光素标记的互补链(Cs2-FAM)和另一条链Cs3结合。这三条链形成了双链结构,荧光不会被Fe3O4/C猝灭。在没有ACE的情况下,Cs2-FAM将处于单链状态,并被Fe3O4/C吸附,Fe3O4/C通过光电子转移猝灭FAM的荧光。该aptasensor在10-1000nM的线性浓度范围内灵敏地检测ACE,检测限为3.41nM。加标ACE在白菜和芹菜样品中的回收率为89.49%至110.76%,具有很高的准确性。
Acetamiprid (ACE) is a highly effective broad-spectrum insecticide, and its widespread use is potentially harmful to human health and environmental safety. In this study, magnetic Fe3O4/carbon (Fe3O4/C), a derivative of metal-organic framework MIL-101 (Fe), was synthesized by a two-step calcination method. And a fluorescent sensing strategy was developed for the efficient and sensitive detection of ACE using Fe3O4/C and multiple complementary single-stranded DNA (ssDNA). By using aptamer with multiple complementary ssDNA, the immunity of interference of the aptasensor was improved, and the aptasensor showed high selectivity and sensitivity. When ACE was present, the aptamer (Apt) combined with ACE. The complementary strand of Apt (Cs1) combined with two short complementary strands of Cs1, fluorophore 6-carboxyfluorescein-labeled complementary strand (Cs2-FAM) and the other strand Cs3. The three strands formed a double-stranded structure, and fluorescence would not be quenched by Fe3O4/C. In the absence of ACE, Cs2-FAM would be in a single-chain state and would be adsorbed by Fe3O4/C, and the fluorescence of FAM would be quenched by Fe3O4/C via photoelectron transfer. This aptasensor sensitively detected ACE over a linear concentration range of 10-1000 nM with a limit of detection of 3.41 nM. The recoveries of ACE spiked in cabbage and celery samples ranged from 89.49% to 110.76% with high accuracy.