PCR-free cascaded CRISPR-Cas13a colorimetric platform (CLAMP) for non-invasive miRNA-based allergen-specific subtyping of allergic rhinitis.

Accurate identification of causative allergens is critical for personalized management of allergic rhinitis (AR), yet current methods often fail to distinguish clinical relevance from sensitization, particularly in polysensitized patients. To address this, we developed CLAMP (Cascaded CRISPR-Cas13a LAMP Colorimetric Assay), a platform that leverages a single Cas13a/crRNA complex to initiate a simplified CRISPR cascade amplification, enabling one-pot two-step detection without tube opening after sample addition. The assay employs a colorimetric readout based on CIELAB ΔE, allowing quantitative biomarker analysis with minimal equipment, requiring only a simple heat source. CLAMP achieves a detection limit of 1.15 × 10-15 M with excellent specificity and a turnaround time under 60 min. In preclinical validation using nasal lavage fluid from 200 allergen-specific AR mouse models, CLAMP enabled allergen-based AR classification via multiplex miRNA detection, achieving 91.5% accuracy in distinguishing major allergen subtypes. This low-cost, non-invasive platform holds strong potential for rapid allergen classification and future translation toward personalized immunotherapy in AR.