Electrochemical staged detection method for multiple helicobacter pylori single-base mutants

The invention belongs to the technical field of biological detection, and relates to an electrochemical staged detection method for multiple helicobacter pylori single-base mutants. An electrochemical sensor adopted in the method comprises a sensing electrode, auxiliary DNA, sgRNA and Cas9 nuclease. The sensing electrode is composed of a conductive substrate, gold nanoparticles, a probe DNA and nano CdS, the two ends of the probe DNA are connected with the gold nanoparticles and the nano CdS respectively, and the conductive substrate is connected with the gold nanoparticles; the probe DNA, the auxiliary DNA and the target DNA can be mutually hybridized to form a Y-shaped structure; the sgRNA and the Cas9 nuclease can form a Cas9/sgRNA compound, and the Cas9/sgRNA compound can be used for destroying a Y-shaped structure, so that the nano CdS is separated from the Y-shaped structure. The total nucleic acid amount and the single-base mutant are detected, so that the infection condition and the drug resistance co