Construction of molecular logic gates using heavy metal ions as inputs based on catalytic hairpin assembly and CRISPR-Cas12a

摘要

We successfully constructed several molecular logic gates using heavy metal ions as inputs based on catalytic hairpin assembly (CHA) and CRISPR-Cas12a. The corresponding DNAzymes were used to recognize heavy metal ions (Hg2+, Cd2+, Pb2+, and Mn2+). The specific cleavage between heavy metal ions and DNAzymes leads to the release of the trigger DNA, which can be used to activate CHA through logic computation. The CHA-generated DNA duplexes contain the protospacer adjacent motifs (PAM) sequence, which can be distinguished by CRISPR-Cas12a. The hybridization interactions between the duplexes and gRNA will activate the trans-cleavage capa-bility of Cas12a, which can cleave the single-stranded DNA (ssDNA) reporter. The separation of the fluorescence group and quench group in ssDNA will generate a high fluorescence signal for readout. Using Hg2+ and Cd2+ as the two inputs, several basic logic gates were constructed, including OR, AND, and INHIBT. Using Hg2+, Cd2+, Pb2+, and Mn2+ as the four inputs, cascaded logic gates were further fabricated. With the advantages of scal-ability, versatility, and logic computing capability, our proposed molecular logic gates can provide an intelligent sensing system for heavy metal ions monitoring.

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