A rapid and sensitive one-pot platform integrating fluorogenic RNA aptamers and CRISPR-Cas13a for visual detection of monkeypox virus.

Abstract

The recent global upsurge in Monkeypox virus (MPXV) outbreaks underscores the critical need for rapid and precise diagnostic solutions, particularly in resource-constrained settings. The gold standard diagnostic method, qRT-PCR, is hindered by its time-consuming nature, requirement for nucleic acid purification, expensive equipment, and the need for highly trained personnel. Traditional CRISPR/Cas fluorescence assays, relying on trans-cleavage of ssDNA/RNA reporters labeled with costly fluorophores and quenchers, pose challenges that limit their widespread application, especially for point-of-care testing (POCT). In this study, we utilized a cost-effective and stable fluorogenic RNA aptamer (Mango III), specifically binding and illuminating the fluorophore TO3-3 PEG-Biotin Fluorophore (TO3), as a reporter for Cas13a trans-cleavage activity. We propose a comprehensive strategy integrating RNA aptamer, recombinase-aided amplification (RAA), and CRISPR-Cas13a systems for the molecular detection of MPXV target. Leveraging the inherent collateral cleavage properties of the Cas13a system, we established high-sensitivity and specificity assays to distinguish MPXV from other Orthopoxviruses (OPVs). A streamlined one-pot protocol was developed to mitigate aerosol contamination risks. Our aptamer-coupled RAA-Cas13a one-pot detection method achieved a Limit of Detection (LoD) of 4 copies of target MPXV DNA in just 40 min. Validation using clinical MPX specimens confirmed the rapid and reliable application of our RAA-Cas13a-Apt assays without nucleic acid purification procedure, highlighting its potential as a point-of-care testing solution. These results underscore the user-friendliness and effectiveness of our one-pot RAA-Cas13a-Apt diagnostic platform, poised to revolutionize disease detection and management.