Table 1. Photophysical properties of probes and their parent fluorophores in 50 mM HEPES buffer.

Dye	λ abs (nm)	λ em (nm)	ε (M–1 cm–1)	Φ a
Coumarin-6H	402	495	43 500	0.92
CoNox-1	295	495	29 500	0.04
Morpholinorhodol	510	535	48 500	0.15
FluNox-1	450	530	15 000	0.08
Si-rhodamine B	645	660	12 500	0.34
SiRhoNox-1	575	660	1250	0.08

^aQuantum yields were determined in 50 nM HEPES buffer (pH 7.4).