Spectral properties of fluorophores.

Compound	λ max a (nm)	λ em a (nm)	ε b (M−1 cm−1)	Stokes shift (nm)	Φ c (%)
Coumarin13d	386	448	36 700	62	70
Fluorescein3bd	490	512	93 000	22	95
3aa	433	535	2110	102	17
3ab	432	527	3066	95	23
3ac	434	542	3613	108	14
3ad	434	538	3790	104	13
3ae	436	543	3588	107	11
3af	437	545	3440	108	12
3ag	434	538	3558	104	16
3ah	434	541	3430	107	17
3ai	434	535	3312	101	19
3aj	435	536	2770	101	15
3ak	435	540	3209	105	14
3al	436	542	3786	106	14
3am	435	543	3418	108	12
3an	433	536	4364	103	19
3ao	434	537	3874	103	18
3ap	432	525	2804	93	22
3aq	434	530	3917	96	18
3ar	433	539	3578	106	14
3as	435	535	2915	100	18
3at	434	538	3250	104	18
3au	434	536	2935	102	17
3av	434	532	3170	98	18
3aw	437	552	3099	115	1
3ax	425	528	3865	103	16
3ba	440	542	2285	102	09
3bb	443	550	3771	107	09
3bc	443	547	2796	104	10
3bd	427	536	3853	109	17
3be	424	535	2458	111	12

^aMeasured in CH₃CN at 200 μM.

^bMolar extinction coefficient.

^cAbsolute fluorescence quantum yield determined with an integrating sphere system.

^dThe structures of coumarin and fluorescein are shown in Fig. 1.