CRISPR-assisted MoS2@TQD nanosheets-based lateral flow assay for dual-mode and sensitive diagnosis of SARS-CoV-2.

Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) assembled lateral flow assay (LFA) have been developed for rapid virus diagnosis, however, the single-mode visual half-quantitative characteristics limit their applications in accurate quantitative diagnosis. Herein, a CRISPR assisted MoS2@TQD (MoS2 nanosheet assembled ternary quantum dot) based colorimetric and fluorescent dual-mode LFA was fabricated for the ultrasensitive and flexible detection of the SARS-CoV-2. Compared with single QDs, MoS2@TQD can provide stable and superior colorimetric/fluorescent signals in various bio-samples. RT-RAA/CRISPR-Cas13 was adopted to couple with MoS2@TQD so that the detection sensitivity can be further enhanced. Based on the dual-mode LFA, the colorimetric visual detection limit was 400 copies/mL, and for fluorescence quantification mode, as low as 250 copies/mL can be obtained. For clinic diagnosis, 35 SARS-CoV-2 positive throat swab samples and 18 negative samples were detected by this LFA, 100% accuracy and 100% consistency with quantitative polymerase chain reaction (qPCR) results can be obtained. It indicated that MoS2@TQD-based dual-mode LFA can be a rapid, sensitive, and accurate detection platform for SARS-CoV-2 and other infectious pathogens in the point-of-care diagnosis.