CRISPR/Cas12a-Loaded intelligent DNA hydrogel for Universal and
Ultrasensitive Exosome Assay
Abstract
Tumor-derived exosomes are crucial for early non-invasive and accurate
tumor diagnosis in clinical. The development of highly sensitive, simple
and intuitive exosome assays has sparked a research upsurge in clinical
diagnostics. Here, we develop a bio-responsive the intelligent DNA
hydrogel loaded with CRISPR/Cas12a for universal and ultrasensitive
detection of the exosomes. The aptamer serves as the target response
unit and switch of the intelligent DNA hydrogel network. The target
competitively disintegrates the region of the DNA linkers then
Cas12a/crRNA encapsulated in the intelligent DNA hydrogel can be
released and activated by the collateral sequence, resulting in a high
fluorescent intensity for exosome detection at the detection limit of
119 particles/μL. Moreover, a prefabricated colorimetric tube is made by
loading a colorimetric filter membrane on the tube lid and intelligent
DNA hydrogel on the tube bottom, which enables one-pot portable
colorimetric detection. Without the need for laboratory instruments and
professionals, this strategy allows for naked eye detection with LOD as
low as 104 particles/μL, and shows great applicability in distinguishing
between healthy individuals, pretreatment patients, and post treatment
patients after obtaining a testable analyte. Collectively, this study
constructs an ultra-sensitive detection platform for exosomes, which
enables one-step sensing and dual signal output, making it a promising
tool for the application of liquid biopsy based on exosomes in clinical
diagnosis.