The coumarin fluorescent probe structure and fluorescent indicator of “application” part.

Fluorescent probe type		Probe structure	Change in fluorescence	Location of coumarin functionalization
Metal ion fluorescent probe	Reacts with Cu2+		41: Fluorescence changed from yellow to bright red	3-Position
			42: Show strong orange fluorescence at 590 nm
			Fluorescence quenching	3-Position
			Show fluorescence enhancement	3-Position
			Show fluorescence enhancement	3-Position
			“Turn-on” probe; from no fluorescent to fluorescent	3-Position
	Reacts with Hg2+		Show strong blue fluorescence	7-Position
			Show a reversible dual chromo- and fluorogenic response	3-Position
			Show fluorescence enhancement	3-Position
	Reacts with Mg2+		Fluorescence changed from weak blue to bright blue	7-Position and 8-position
			Fluorescence changed from non to strong red	3-Position
			Show fluorescence enhancement	3-Position
			Show fluorescence enhancement	3-Position
	Reacts with Zn2+		Show significant increase in fluorescence at 500 nm	7-Position
			Absorption spectrum shifted toward longer wavelengths, and the fluorescence is enhanced	7-Position and 8-position
pH fluorescent probe	Reacts with H+		As the pH decreased, the absorption spectrum gradually red-shifted	3-Position
			When the pH is low (below 3.5), the fluorescence at 460 nm is quenched	3-Position
			When the probe interacted with H+, the coumarin release decreased at 477 nm and the rhodamine release increased at 582 nm	3-Position
Oxygen and sulfide fluorescent probes	Reacts with oxygen		I 651/I495 increased significantly	3-Position
			New emission appeared at 580 nm. The emission intensity increased with the increase of hypochlorite dose, and the fluorescence intensity decreased at 470 nm	3-Position
	Reacts with H2S		Fluorescence quenching	Functionalized position of fluorescent probe based on FRET mechanism: 3-position
				Functionalized position of fluorescent probe based on ICT mechanism: 7-position
			Show fluorescence enhancement	7-Position
			Generates a large emission displacement	3-Position
Environmental polarity probes	Environmental polarity		Show orange-yellow colour change and simultaneous fluorescence increase	3-Position
			When the polarity of environment decreases, it shows strong fluorescence	66e–g: 4-position