The accurate and sensitive detection of
glucose from secretory clinical samples, such as tears and saliva, remains a great challenge. In this research, a novel ultrasensitive
glucose detection method consisting of a
glucose oxidase (GOx), pistol-like
DNAzyme (PLDz), and CRISPR-Cas12a system is proposed. First, the oxidation of
glucose catalyzed by GOx leads to the production of H2O2; the self-cleavage activity of PLDz is activated after recognition of the produced H2O2. The two procedures triggered by COx and PLDz play an important role in accurately identifying
glucose and converting
glucose signals to
nucleic acids. The obtained PLDz fragments can be recognized by the Cas12
enzyme and thus activate the trans-cleavage activity of the Cas12a
enzyme. Finally, the surrounding reporter probes are cut by the Cas12a
enzyme to produce fluorescence signals. In summary, an ultra-sensitive and specific fluorescence method has been developed for
glucose detection from secretory clinical samples, which could potentially contribute to the noninvasive diagnosis of
diabetes mellitus.