Fig. 4. CRISPR-based strategies used in the detection of non-nucleic acid targets. (A) Molecular translation mechanisms for the CRISPR-based POC detection for non-nucleic acid targets. (B) Detection strategy and workflow of the fDNAs-regulated CRISPR-Cas12a sensor for adenosine triphosphate (ATP) using a hand-hold portable device. Target binding to the fDNA in the presence of ATP can induce the DNA activator to dehybridize from the fDNA and become an “open activator” that binds to and activates the Cas12a. Reproduced from ref. 65 with permission. Copyright 2020 American Chemical Society. (C) Scheme of CLISA for femtomolar high throughput detection of proteins assisted by CRISPR-Cas13a. The capture antibody binds to the antigen of interest first, followed by a biotinylated detection antibody that is streptavidin-linked to a biotin-dsDNA template. Following transcription, the amplified RNAs activate trans-cleavage, allowing for detection. Reproduced from ref. 68 with permission. Copyright 2020 American Chemical Society.