Sulfadimethoxine (SDM) poses a potential threat to the food safety and human health due to its overuse in aquatic or animal husbandry. Therefore, a rapid and sensitive identification method is urgently needed to monitor SDM in food and the environment. Herein, a “turn-on” fluorescence aptasensor based on entropy-driven catalysis (EDC) and CRISPR-Cas12a was proposed for the sensitive determination of SDM. Particularly, to overcome the barriers of coupling the EDC circuit to CRISPR-Cas12a, a novel EDC circuit with a Y-shaped substrate scaffold was designed to lock the activation sequence of CRISPR-Cas12a. Multifunctional hollow flower-like microsphere H-Fe₃O₄@MoS₂ was synthesized as a fluorescence resonance energy transfer (FRET) energy acceptor for ssDNA-FAM to quenching its fluorescence. In the presence of the SDM, activated Cas12a-crRNA-A rapidly cleaved the ssDNA-FAM adsorbed on the MoS₂ nanosheet to restore the fluorescence signal in the reporter system, which could be utilized to determine the concentration of SDM. Due to the prominent quenching properties and rapid magnetic separation of H-Fe₃O₄@MoS₂ along with the double signal amplification of locking-EDC-CRISPR-Cas12a, the developed aptasensor exhibited the appealing analytical performance with a log-linear range of 0.005-100 ng mL^-1 and a limit of detection of 2.86 pg mL^-1. Furthermore, the practicability and credibility of the locking-EDC-Cas12a sensoring strategy were validated by spiked recovery experiments of SDM in real samples. Hence, the current strategy provides a promising candidate analytical tool for food and environmental safety.

磺胺二甲氧嘧啶 (SDM) 由于在水产或畜牧业中的过度使用，对食品安全和人类健康构成潜在威胁。因此，迫切需要一种快速灵敏的鉴定方法来监测食品和环境中的SDM。在此，提出了一种基于熵驱动催化 (EDC) 和 CRISPR-Cas12a 的“开启”荧光适体传感器用于 SDM 的灵敏测定。特别是，为了克服将 EDC 电路耦合到 CRISPR-Cas12a 的障碍，设计了一种具有 Y 形底物支架的新型 EDC 电路来锁定 CRISPR-Cas12a 的激活序列。多功能空心花状微球 H-Fe ₃ O ₄ @MoS ₂被合成为 ssDNA-FAM 的荧光共振能量转移 (FRET) 能量受体以淬灭其荧光。在SDM存在下，活化的Cas12a-crRNA-A迅速切割吸附在MoS ₂纳米片上的ssDNA-FAM，恢复报告体系中的荧光信号，可用于测定SDM的浓度。由于H-Fe ₃ O ₄ @MoS ₂突出的猝灭特性和快速磁分离以及locking-EDC-CRISPR-Cas12a的双重信号放大，开发的aptasensor表现出吸引人的分析性能，其对数线性范围为0.005-100 ng mL ^-1和检测限为 2.86 pg mL ^-1. 此外，锁定-EDC-Cas12a 传感策略的实用性和可信性通过 SDM 在实际样品中的加标回收实验得到验证。因此，当前的策略为食品和环境安全提供了一个有前途的候选分析工具。