The invention provides a memristor. The memristor comprises a substrate, a reaction electrode, a non-reaction electrode and a conversion layer positioned between the reaction electrode and the non-reaction electrode; the reaction electrode, the conversion layer and the non-reaction electrode commonly constitute a sandwich structure; the sandwich structure is arranged on the surface of the substrate; the material of the conversion layer is M-Ge-N, the material of the reaction electrode is M, and the M is silver or copper and N is selenium or tellurium; the reaction electrode is used for oxidizing M into M ions under induction of an electric field; the M ions enter the conversion layer and participate in forming an MN nanowire at a contact interface of the reaction electrode and the conversion layer or at a defect of the conversion layer M-Ge-N; and the MN nanowire obtains various sizes and shapes under control of an amplitude value of the electric field and electric field action time; the memristor has strong absorption on light with different frequencies, and generates LSPR phenomenon of different response wave lengths so as to realize sensing for various kinds of materials. The invention also provides a sensor containing the memristor.