Upconversion-mediated CRISPR-Cas12a biosensing for sensitive detection of ochratoxin A

The CRISPR-Cas system has achieved breakthrough applications in the field of molecular diagnostics. CRISPR/Cas12a can accurately identify subtle changes in a target nucleic acid sequence and has a wide range of applications such as in highly sensitive detection methods. In this study, an upconversion-magnetic probe-DNA-Fe3O4 probe was designed to replace traditional fluorescent probes using nucleic acid aptamers to design a biosensing method powered by CRISPR/Cas12a. The CRISPR/Cas12a technology can be widely used for sensitive, rapid, and stable detection of ochratoxin A. In our sensing strategy, the ochratoxin A capture probe was used to capture ochratoxin A and release the Cas protein activation chain, further triggering the single-stranded DNA degradation activity of CRISPR/Cas12a and removal of the fluorescent probe to generate a fluorescent signal. Compared with traditional commercial kits, our method was more rapid and exhibited comparable detection capability.