Table 1.

MPM maxima values for endogenous fluorophores of the skin and ZnO NP (recreated with permission from Ref. 17).

Component	Excitation wavelength (nm)	Emission wavelength (nm)	Fluorescence lifetime (ns)
NAD(P)H free	720 to 760	460	0.3
NAD(P)H bound	720 to 760	440	2.0 to 2.3
FAD	860 to 920	530	5.2
Keratin	720 to 800	420 to 580	0.4-2.3
Elastin	860 to 880	420 to 460	0.2/2.5
Collagen	860 to 900	430 to 450	0.3/2.0
Melanin	720 to 760, 920	440, 520, 575	0.1/1.9/8.0
ZnO NP	710 to 840	370 to 600	$>0.15$