The invention discloses a flavonol-based fluorescent probe for continuously detecting
hydrogen sulfide and
hypochlorous acid as well as a preparation method and application of the flavonol-based fluorescent probe. The flavonol-based fluorescent probe is 3-(2, 4-dinitrophenoxy)-7-(4-(diphenylamino) phenyl)-2-(4-(thiomorpholinophenyl)
chromone, and the
structural formula of the flavonol-based fluorescent probe is shown in the specification. According to the invention, 7-(4-(diphenylamino) phenyl)-3-hydroxy-2-(4-thiomorpholinophenyl)
chromone is used as an initial
raw material, and the 7-(4-(diphenylamino) phenyl)-3-hydroxy-2-(4-thiomorpholinophenyl)
chromone and 2, 4-
dinitrofluorobenzene are subjected to
nucleophilic substitution reaction to obtain the compound 3-(2, 4-dinitrophenoxy)-7-(4-(diphenylamino) phenyl)-2-(4-(thiomorpholinophenyl) chromone. The compound is firstly subjected to selective thiolysis reaction under the action of
hydrogen sulfide, the
fluorescence color of a solution of the compound is changed from colorless to bright orange under the
irradiation of
ultraviolet light with the
wavelength of 365 nm, then
hypochlorous acid is continuously added into the solution, and the compound can be further subjected to specific oxidation reaction with the
hypochlorous acid, so that the compound can be obtained. And the
fluorescence color of the solution is changed from bright orange to bright cyan. Therefore, the compound can be used as a fluorescent probe for continuously detecting
hydrogen sulfide and hypochlorous acid, has the advantages of low
detection limit, high response speed, good light stability, wide pH application range and the like, and shows a good application prospect.