Aptamer-CRISPR Glucose Transducer for point-of-care IgE detection

Immunoglobulin E (IgE) is a critical biomarker for the diagnosis and therapeutic monitoring of allergic diseases. Conventional IgE detection methods (e.g., ELISA, ImmunoCAP) generally offer satisfactory sensitivity but require hours to days, rely on specialized equipment and trained personnel, and are unsuitable for point-of-care or home-based testing. Here, we developed a portable point-of-care testing platform termed Aptamer-CRISPR Glucose Transducer (ACGT), based on aptamer competition and CRISPR-Cas12a trans-cleavage. The platform employs the D17.4 aptamer as the molecular recognition element. In the presence of target IgE, the aptamer specifically binds IgE, triggering a strand displacement reaction that releases the blocker as ssDNA. This released blocker (now serving as the trigger) activates the trans-cleavage of Cas12a, which cleaves ssDNA linkers on magnetic beads, thereby releasing invertase into the supernatant. The released invertase hydrolyzes sucrose into glucose, which is quantitatively measured using a personal glucose meter. The method achieves a detection limit as low as 76.5 kU/L, with a total assay time of approximately 80 min. By integrating the signal amplification capability of CRISPR with the accessibility of glucose-based transduction, the ACGT platform provides a sensitive, cost-effective, and user-friendly solution for allergen diagnosis and biomarker monitoring in decentralized settings, offering great potential for primary care and home-based testing.