Development of a CRISPR/Cas12a-facilitated fluorescent aptasensor for sensitive detection of small molecules.

The integration of Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) and CRISPR-associated proteins (Cas) exhibits superior performance in biosensor construction. And the distinctive role of aptamers in target recognition has long been a focal point of research. Through the combination of Cas12a with cis-cleavage activity and aptamer with specific recognition, a simple and rapid fluorescent biosensor has been constructed. Interestingly, with modified fluorescent and quenching groups at two ends, aptamers play a dual role: primarily as the elements for target recognition and additionally functioning act as the fluorescent probe for signal output. Coupling with cis-cleavage of Cas12a, the demand of additional signal probes is eliminated, thus simplifying the reaction system and enhancing result accuracy. Taking okadaic acid (OA) as a representative small molecule model to evaluate the sensor's performance, a simple and straightforward detection method was established. Following this, the universality of the constructed fluorescent aptasensor was validated by incorporating an adenosine triphosphate (ATP) aptamer. Consequently, the CRISPR/Cas12a-assisted aptasensor was demonstrated to serve as a versatile detection platform for small molecules in food safety and clinical diagnostics. In the forthcoming research endeavors, it can be further extended for applications in environmental analysis and various other fields.