▎ 摘　　要

NOVELTY - Coumarin-functionalized graphene quantum dot fluorescent probe (I) is new. USE - (I) is useful for detecting cyanides and ascorbic acid (claimed). ADVANTAGE - (I) solves the technical problems of low sensitivity and high biological toxicity of existing fluorescent probes for detecting cyanides and ascorbic acid. DETAILED DESCRIPTION - Coumarin-functionalized graphene quantum dot fluorescent probe of formula (I) is new. INDEPENDENT CLAIM is also included for: (1) preparation of (I); (2) use of (I) for detecting cyanides comprising (i) taking mixed solution of dimethylformamide and water in a volume ratio of 1:1 as dispersant, adding 30 mg/l coumarin-functionalized graphene quantum dot fluorescent probe into the dispersant to obtain probe dispersion liquid, (ii) adding test sample into probe dispersion, mixing uniformly to obtain sample dispersion, (iii) testing dispersion of the probe dispersion using fluorescence spectrophotometer at emission wavelength of 507 nm and fluorescence intensity of A0,and then test the fluorescence intensity A1 of the sample dispersion at emission wavelength of 507 nm, when A1 less than or equal to 30% A0, then determining that the test sample contains cyanides; and (3) use of (I) for detecting ascorbic acid comprising (i) taking mixed solution of 30 mg/l concentration of coumarin-functionalized graphene quantum dot fluorescent and 600-1166 mu mol/l concentration of tetrabutylammonium as mixture A, and dimethylformamide and water in a volume ratio of 1:1 as solvent, adding A into solvent, and mixing uniformly to obtain probe dispersion liquid, (ii) adding test sample to the probe dispersion, mixing uniformly to obtain sample solution, (iii) testing the dispersion of the probe dispersion with fluorescence spectrophotometer at emission wavelength of 507 nm and fluorescence intensity is B1, and the fluorescence intensity of the sample solution is B2 with emission wavelength is 507 nm, when B1 is less than or equal to 30% B2, then determining that the test sample contains ascorbic acid.