CRISPR-Hg: Rapid and visual detection of Hg 2+ based on PCR coupled with CRISPR/Cas12a

Mercury (Hg) is a notorious toxic heavy metal, causing neurotoxicity and liver damage, posing grave threats to human health and environmental safety. There is an urgent imperative for developing novel Hg detection methods. In this work, we developed a CRISPR-based method for Hg detection named CRISPR-Hg. A CRISPR/Cas12a system was employed and could be activated by the PCR product, generating fluorescence signals based on the trans-cleavage activity. CRISPR-Hg exhibited remarkable selectivity and specificity, achieving a detection limit of 10 pM and minimal interference with background signals. This approach has been successfully applied to detect Hg in real samples, including water, soil, and mushroom. Ulteriorly, a portable device was devised to streamline the readout of fluorescence signals by a smartphone within 30 min. We offer an affordable, highly selective and visually interpretable method for Hg detection, with the potential for broad application in Hg monitoring for food safety and public health.