▎ 摘　　要

NOVELTY - A coumarin functionalized graphene oxide compound (I), is new. USE - Coumarin functionalized graphene oxide compound used as fluorescent probe for detecting cyanide ion in water system (claimed) during water quality testing. ADVANTAGE - The fluorescent probe enables detection of cyanide ions with excellent detection reversibility. DETAILED DESCRIPTION - A coumarin functionalized graphene oxide compound of formula (I), is new. INDEPENDENT CLAIMS are included for the following: (1) preparation of compound (I), which involves adding graphene oxide to a toluene solution, ultrasonically dispersing for 1-3 hours, adding 3-glycidoxypropyltriethoxysilane under constant stirring, reacting the mixed solution at 30-40 degrees C for 3-4 hours, refluxing for 3-5 hours to obtain a black reaction liquid, cooling, filtering, rinsing with toluene, drying in vacuum, adding resulting intermediate (a) to toluene, ultrasonically dispersing for 1-2 hours, adding resulting solution to ((E)-((7-(diethylamino)-2-oxo-2H-chromen-3-yl)methylidene)amino)thiourea of formula (II), stirring, passing nitrogen, refluxing for 24-36 hours, filtering, rinsing and purifying; and (2) application of coumarin-functionalized graphene oxide as fluorescent probe for detecting cyanide ions in water system.