Chemiluminescence resonance energy transfer as a simple and sensitive readout mode for a CRISPR/Cas12a-based biosensing platform

Various CRISPR/Cas12a-based biosensing systems have been developed in the past few years, and most of these systems used Taqman probes to report signals through fluorescence resonance energy transfer (FRET). In this study, we explored chemiluminescence resonance energy transfer (CRET) as the readout mode for CRISPR/Cas12a-based biosensing. The chemiluminescence (CL) reaction of bis(2,4,6-trichlorophenyl) oxalate (TCPO) and H2O2 was used to excite the fluorophore dye of the Taqman probe. Different from FRET, CRET does not need external excitation light, which can effectively avoid autofluorescence and photobleaching. The detection limit of this CRET readout mode was estimated to be 10 pM for target DNA, which was about 8 times lower than that of the widely used FRET readout mode. These results suggest that CRET can serve as a rapid, sensitive and simple readout mode of CRISPR/Cas12-based biosensing, and can further enrich the toolbox of CRISPR/Cas12-based biosensing.