Integrating high mannose-binding aptamer and CRISPR/Cas12a machinery for the remote detection of cell surface high mannose

High mannose is overexpressed on the cell surface during carcinogenesis; however, there are currently no efficient techniques for its detection. Herein, we propose an assay called RADAR (remote high mannose detection on cell surface with CRISPR) for the quantification of high mannose, leveraging the integration of high mannose-binding aptamer and CRISPR technique. The high mannose-binding aptamer is hybridized with a locker, which is released upon specific binding to high mannose. The released locker then activates CRISPR/Cas12a to produce a fluorescence signal. The "remote" concept in RADAR refers to the recognition of high mannose occurring on the cell surface, while signal generation takes place in a solution separate from the target. This feature makes RADAR suitable for the detection of suspended bio-samples without the need for sophisticated imaging. RADAR can detect high mannose Man9 with a limit of detection of 2.5 nM, distinguish cancer cells from non-cancerous cells, and profile high mannose level in human serum for potential non-small cell lung cancer (NSCLC) diagnosis. This work represents the first attempt to integrate CRISPR technology into the aptasensing of high mannose, which may serve as a synthetic biology-enabled tool in glycochemistry and glycobiology. •CRISPR/Cas12a was first applied in the detection of cell surface high mannose.•High mannose aptamer was applied in biosensing for the first time.•This assay is suitable for the detection of bio-samples without sophisticated imaging.