Cas12a-assisted split crRNA complex for analysis and detection of diverse entities.

The Cas12a-crRNA system possesses inherent sequence-specific recognition of double-stranded DNA/single-stranded DNA (dsDNA/ssDNA) coupled with trans-cleavage activity toward ssDNA, making it a powerful tool for nucleic acid diagnostics. However, its application beyond nucleic acid targets remains challenging, limiting its potential as a universal detection platform. In this study, we systematically explore the key parameters governing the activation of a Cas12a-split crRNA system and established a comprehensive set of design guidelines. Building on these findings, we developed CASCADE (Cas12a-Assisted Split crRNA Complex for Analysis and Detection of Diverse Entities), an adaptable detection platform that extends Cas12a's application beyond nucleic acids. Using microRNA as a model, we validated the system's sensitivity, specificity, and mismatch discrimination capability. Additionally, we successfully demonstrated its capability for non-nucleic acid target detection by detecting tobramycin, kanamycin, biotin, and tetracycline repressor protein, confirming its sensitivity and specificity. Finally, by integrating a lateral flow assay (LFA), we enhanced the portability of CASCADE, enabling user-friendly, on-site detection. This work expands the application scope of the Cas12a system and offers a promising strategy for point-of-care diagnostics or environmental monitoring.