Aflatoxin B1 (AFB1) contamination in food threatens global food safety, and rapid quantitative detection of AFB1 remains a challenge. Herein, a novel fluorescence biosensor was developed for AFB1 detection based on CRISPR/Cas12a and MXenes. Specifically, the well-designed activator was locked by dual-AFB1 aptamers, Cas12a was directly linked to crRNA to form inactivated complexes, and MXenes efficiently adsorbed FAM fluorophore-modified single-stranded DNA (ssDNA-FAM), quenching its fluorescence. In the presence of AFB1, the activator was released due to the preferential binding of the aptamer to AFB1, and the released activator then activated the trans-cleavage activity of Cas12a to indiscriminately cleave ssDNA on MXenes, leading to the recovery of the fluorescence signal. The fluorescent biosensor had a wide detection range from 0.001 to 80 ng mL⁻¹, a detection limit of 0.92 pg mL⁻¹, and the ability to detect within 80 min. More importantly, the platform demonstrates excellent detection performance in real peanut samples.

食品中的黄曲霉毒素 B1 (AFB1) 污染威胁着全球食品安全，AFB1 的快速定量检测仍然是一个挑战。在此，基于 CRISPR/Cas12a 和 MXenes 开发了一种用于 AFB1 检测的新型荧光生物传感器。具体来说，精心设计的激活剂被双 AFB1 适体锁定，Cas12a 直接连接到 crRNA 形成失活复合物，MXenes 有效吸附 FAM 荧光团修饰的单链 DNA (ssDNA-FAM)，猝灭其荧光。在 AFB1 存在的情况下，由于适配体优先结合 AFB1，激活剂被释放，释放的激活剂随后激活反式Cas12a 的切割活性可以不加区别地切割 MXenes 上的 ssDNA，从而导致荧光信号的恢复。该荧光生物传感器具有0.001至80 ng mL ^-1的宽检测范围，0.92 pg mL ^-1的检测限，以及在80分钟内检测的能力。更重要的是，该平台在真实花生样品中展示了出色的检测性能。