CRISPR/Cas12a powered sandwich aptamer assay coupled with effective DNA self-assembly amplification for sensitive detection of immunoglobulin E

Sensitive and accurate detection of protein biomarkers is of significance for disease diagnosis. Recently, CRISPR/Cas system has emerged as a powerful signal amplifier in the field of sensing technology. We report a CRISPR/Cas12a powered sandwich aptamer assay (CAPSA) for protein analysis coupled with effective DNA self-assembly amplifications. The target protein is sandwiched between the capture antibody on the microplate and the aptamer detection probe. The aptamer is engineered with a specific initiator to trigger streptavidin (SA)-biotin-based dendritic amplification reaction, yielding a DNA polymer with multiple repeats of active DNA (acDNA) as Cas12a recognition sites. With the addition of Cas12a reporter system, the acDNA activates Cas12a to cleave DNA reporters, producing amplified fluorescence signals. Particularly, we also describe an innovative one-step DNA self-assembly amplification strategy to meet the demands for fast point-of-care testing, which can be directly integrated into the CAPSA without additional operation steps. The proposed methods were demonstrated by detecting immunoglobulin E (IgE), which plays a vital role in allergic reactions. Our proposed one-step DNA self-assembly amplified CAPSA enabled us to detect IgE as low as 0.6 pM, exhibiting high selectivity and satisfactory performance in complex sample analysis. Collectively, this method combines the efficient signal amplification of DNA self-assembly with the high trans-cleavage activity of Cas12a, offering a simple, universal, and double-amplified approach for sensitive analysis of protein biomarkers. [Display omitted] •A CRISPR/Cas12a powered sandwich aptamer assay (CAPSA) is developed for IgE detection.•Streptavidin-biotin powered DNA assembly amplification combined with CRISPR/Cas12a improving sensitivity.•The proposed one-step DNA assembly is directly integrated into CAPSA without additional operation steps.•DNA assembly amplified CAPSA were sensitive and selective for the detection of IgE.