Locking-Fluorescence Signals Regulated CRISPR/Cas12a Biosensor Based on Metal–Organic Framework for Sensitive Detection of Salmonella typhimurium

• Published in: Journal of agricultural and food chemistry 2024-11, Vol.72 (46), p.25987-25996
• Main Authors: Zhao, Yan, Yu, Qianqian, Duan, Miaolin, Zhang, Qi, Li, Zhishang, Zhang, Yan, Liu, Yana, Wang, Han, Li, Xingmin, Dai, Ruitong, Jia, Fei
• Format: Article
• Language: English
• Subjects: New Analytical Methods
• ISSN: 0021-8561; 1520-5118; 1520-5118
• DOI: 10.1021/acs.jafc.4c07681

The efficient, sensitive, and rapid detection of Salmonella typhimurium (S. typhimurium) in food and food products is important to ensure food safety and health. This study developed a fluorescence biosensing assay that integrated recombinase-aided amplification (RAA) and CRISPR/Cas12a with a zeolitic imidazolate framework-8@fluorescein sodium (ZIF-8@FLS) nanocomposite for the sensitive detection of S. typhimurium. In this approach, using RAA as a preamplification module, CRISPR/Cas12a-AChE as a target recognition and dual-enzyme cascade amplification module, and the prepared ZIF-8@FLS with high porosity and rapid pH responsiveness as a fluorescence signal explosive amplification module, the RAA-CRISPR/Cas12a-ZIF-8@FLS biosensor was constructed. Under optimal conditions, it exhibited an excellent linear relationship for S. Typhimurium, with a sensitive detection limit as low as 1.3 × 102 CFU/mL and could complete sample detection within 2 h relying on the RAA and ZIF-8@FLS explosive fluorescence rapid response, demonstrating its significant advantages in specificity, sensitivity, and reliability in food-borne pathogens detection.