A universal nucleic acid detection platform combing CRISPR/Cas12a and strand displacement amplification with multiple signal readout

Rapid and sensitive detection of nucleic acids has become crucial in various fields. However, most current nucleic acid detection methods can only be used in specific scenarios, such as RT-qPCR, which relies on fluorometer for signal readout, limiting its application at home or in the field due to its high price. In this paper, a universal nucleic acid detection platform combing CRISPR/Cas12a and strand displacement amplification (CRISPR-SDA) with multiple signal readout was established to adapt to different application scenarios. Nucleocapsid protein gene of SARS-CoV-2 (N gene) and hepatitis B virus (HBV) DNA were selected as model targets. The proposed strategy achieved the sensitivity of 53.1 fM, 0.15 pM, and 1 pM for N gene in fluorescence mode, personal glucose meter (PGM) mode and lateral flow assay (LFA) mode, respectively. It possessed the ability to differentiate single-base mismatch and the presence of salmon sperm DNA with a mass up to 105-fold of the targets did not significantly interfere with the assay signal. The general and modular design idea made CRISPR-SDA as simple as building blocks to construct nucleic acid sensing methods to meet different requirements by simply changing the SDA template and selecting suitable signal report probes, which was expected to find a breadth of applications in nucleic acids detection.