▎ 摘　　要

NOVELTY - The sensor has substrate layer, graphene layer, metal electrode and identification probe molecules. The identification probe molecule comprises pyrene, perylene or anthracene specific group, and active ester for ammonia nitrogen ion connection. USE - Sensor based on graphene FET field effect transistor used in ammonia nitrogen ion detection system for detecting ammonia nitrogen in solution such as indigo phenol blue method, Nashi reagent method, electrode method, salicylic acid colorimetric method and ion chromatography. ADVANTAGE - The sensor combines an organic biological probe and graphene, so that a sample to be detected has super-sensitivity, and can be used for quickly and accurately measuring ammonia nitrogen concentration. A graphene layer is plated on the substrate material containing high-k dielectric layer by wet method. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (a) a preparation method of sensor based on graphene FET field effect transistor; (b) an ammonia nitrogen ion detection system. DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of a sensor based on graphene FET field effect transistor used in ammonia nitrogen ion detection system for detecting ammonia nitrogen in solution. (Drawing includes non-English language text)