Zhang Yali, Dong Xingpeng, Jiang Cuijuan, Yu Yanyan, Zhang Haiyan, Fu Jianjie, Su Gaoxing, Liu Yin
Key Laboratory of Inflammation and Molecular Drug Targets of Jiangsu Province, School of Medicine, School of Pharmacy, Nantong University, Nantong 226001, China.
School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China; Key Laboratory of Inflammation and Molecular Drug Targets of Jiangsu Province, School of Medicine, School of Pharmacy, Nantong University, Nantong 226001, China.
Talanta. 2025 May 1;286:127491. doi: 10.1016/j.talanta.2024.127491. Epub 2024 Dec 29.
Tetracycline (TC) is widely used in veterinary medicine and animal feed; however, TC residues in food pose a risk to human health. Thus, the sensitive and selective detection of TC is needed to ensure food safety. Herein, we developed a CRISPR-Cas12a biosensor with competitive aptamer binding to detect TC residues. The aptasensor, formed by hybridizing activator DNA with TC-specific aptamers on streptavidin-modified magnetic beads, releases activator DNA in a TC concentration-dependent manner. This activated the Cas12a-crRNA complex, which cleaved single-strand DNA reporters to generate a detectable fluorescence signal. The TC signal was amplified through a two-step incubation reaction, with a detection limit as low as 9.45 × 10 μg L. The assay showed high selectivity and good recovery rates in various biological samples (e.g., honey, milk, fish), demonstrating the applicability of the biosensors in pollutant detection.
四环素（TC）在兽医学和动物饲料中广泛使用；然而，食品中的TC残留对人类健康构成风险。因此，需要灵敏且选择性地检测TC以确保食品安全。在此，我们开发了一种具有竞争性适体结合的CRISPR-Cas12a生物传感器来检测TC残留。该适体传感器由激活剂DNA与链霉亲和素修饰磁珠上的TC特异性适体杂交形成，以TC浓度依赖的方式释放激活剂DNA。这激活了Cas12a-crRNA复合物，其切割单链DNA报告分子以产生可检测的荧光信号。TC信号通过两步孵育反应进行放大，检测限低至9.45×10 μg L。该测定法在各种生物样品（如蜂蜜、牛奶、鱼）中显示出高选择性和良好的回收率，证明了该生物传感器在污染物检测中的适用性。
