Ultrasensitive detection of monkeypox virus: harnessing synergistic CRISPR-driven signal amplification on a DNA tetrahedron-mediated sensing interface.

Rapid and ultrasensitive detection of emerging infectious diseases is critical for public health security. Herein, an electrochemical biosensor was developed for ultrasensitive detection of monkeypox virus (MPXV) by integrating CRISPR/Cas12a-driven signal amplification strategy with tetrahedral DNA nanostructure (TDN)-based sensing interface. The added MPXV DNA can efficiently activate the cleavage activity of Cas12a protein, thereby mediating the CRISPR-driven hybridization chain reaction (HCR) on TDN sensing interface. The horseradish peroxidase (HRP)-labeled HCR product can catalyze 3,3',5,5'-tetramethylbenzidine (TMB) and hydrogen peroxide (H2O2) reaction to generate an amplified electrochemical signal. Based on the signal change, the CRISPR-driven electrochemical biosensor exhibited better detection performance comparable to those of pre-amplification CRISPR-based biosensors for MPXV detection, including wide linear range, an ultralow detection limit, exceptional selectivity against non-target viruses (CPXV, ETCV, VZV, HSV), high reproducibility and accepted stability. Integrated with a smartphone-based portable device, the designed point-of-care testing (POCT) electrochemical biosensor can accurately detect MPXV in 10 % human saliva. This work provides a promising sensing platform for rapid, accurate and on-site detection of infectious diseases.