▎ 摘　　要

NOVELTY - Nucleic acid detection system has a substrate having a substrate surface and at least two electrodes. Linking molecule has a first ligand bound to the substrate surface and a second ligand bound to clustered regularly interspaced short palindromic repeats-associated (Cas) enzyme. The Cas enzyme binds to the second ligand of the linking molecule and forms an enzyme complex with a guide nucleic acid. The Cas enzyme comprises Cas12 (type VA), Cas13 (type VI) and Cas14 (type VF). Guide nucleic acid comprises sequences capable of binding to the Cas enzyme and the target nucleic acid, respectively. Reporter nucleic acid comprises a non-specific sequence. USE - Nucleic acid detection system for detecting nucleic acid, screening candidate guide nucleic acid (all claimed). ADVANTAGE - The system has excellent signal-to-noise ratio, sensitivity can reach aM level, and detection time is greatly shortened. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) a nucleic acid detection method, which involves: (a) adding a sample to be tested to the substrate surface of the detection system; (b) applying a current to the substrate; (c) measuring the current change on the surface of the substrate, and determining whether the target nucleic acid exists in the sample to be tested with specific to the current change; (2) a nucleic acid detection system array, which has a substrate having a set of substrate surfaces and at least two electrodes, a set of linking molecules, a set of guide nucleic acids comprising sequences capable of binding to a Cas enzyme and a target nucleic acid, respectively, the set of guide nucleic acids respectively binding to a set of the same or different target nucleic acids, and a reporter nucleic acid comprising a non-specific sequence; (3) a screening method for a candidate guide nucleic acid, which involves: (a) adding a composition comprising a target nucleic acid to the array of nucleic acid detection systems; (b) applying a current to the substrate; (c) measuring the current change on the surface of the substrate, and screening the guide nucleic acid with specific to the current change.