Active CRISPR-Cas12a on Hydrophilic Metal–Organic Frameworks: A Nanobiocomposite with High Stability and Activity for Nucleic Acid Detection

CRISPR-Cas12a is an accurate and responsive biosensing technique, but its limited stability has restricted its widespread applications. To address this, we propose a strategy using metal–organic frameworks (MOFs) to protect Cas12a from harsh environments. After screening multiple candidate MOFs, it was found that hydrophilic MAF-7 is highly compatible with Cas12a, and the as-formed Cas12a-on-MAF-7 (COM) not only retains high enzymatic activity but also possesses excellent tolerance to heat, salt, and organic solvents. Further investigation showed that COM can serve as an analytical component for nucleic acid detection, resulting in an ultrasensitive assay for SARS-CoV-2 RNA detection with a detection limit of 1 copy. This is the first successful attempt to create an active Cas12a nanobiocomposite that functions as a biosensor without the need for shell deconstruction or enzyme release.