Hollow covalent organic framework-sheltering CRISPR/Cas12a as an in-vivo nanosensor for ATP imaging

Abstract

In addition to applications in genome editing, clustered regularly interspaced short palindromic repeats (CRISPR) have recently been engineered for medical diagnostics based on their trans-cleavage activity owing to their high base resolution and isothermal signal amplification. However, trans-cleavage activity is too fragile to be applied in vivo. Herein, we introduce a hollow covalent organic framework (COF)-sheltering CRISPR/aptamer-based sensor (h-CCS) for ATP imaging in living animals. The CRISPR/aptamer-based complex is comprised of the CRISPR-Cas12a system, fluorophore quencher-labeled single-stranded DNA substrate (ssDNA-FQ), and a DNA activator that pre-hybridizes with ATP aptamer to prevent the trans-cleavage activity of the Cas12a system in the absence of ATP. After being encapsulated in a hollow COF, the constructed nanoreactor is highly robust and can be lit up by ATP for in vivo imaging. Considering the unique properties of h-CCS, this strategy offers great potential to broaden applications of not only CRISPR-Cas systems but also other proteins in porous matrixes for clinical diagnostics, medical research, and biomimetic nanodevices.