▎ 摘　　要

(CN212845032-U) NOVELTY - The utility model claims a repeatedly using SERS sensor for detecting heavy metal ion, comprising a porous gallium nitride/silver/gold/single-layer graphene multi-layer composite structure, heavy metal ion probe chain of fluorescent mark; and a heavy metal ion reaction chain; the single-layer graphene upper surface of the porous gallium nitride/silver/gold/single-layer graphene multi-layer composite structure fixes the heavy metal ion probe chain marked by fluorescence by physical adsorption; obtaining the strongest fluorescence molecular Raman signal; the heavy metal ion reaction chain is combined with heavy metal ion probe chain and then quenching fluorescence molecule Raman signal to obtain SERS sensor. The SERS sensor can be used for many times by re-adding heavy metal ion reaction chain on the surface of the sensor after using. The advantages are as follows: it has obvious enhancing effect, stable detection signal, good detection selectivity, multiple times of repeated use and low cost. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method for preparing a reusable SERS sensor. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of a reusable SERS sensor.