Table 1.

Optical properties of screened aldehydes and common probes

Aldehyde and common probe	UV absorption		Fluorescence
	λmax (nm)	εmaxa	Ex (nm)b	Emmax (nm)c	Stokes' shift (nm)	Relative intensityd
2-Naphthaldehyde	292	12.7	344	444	100	100
6-Methoxy-2-naphthaldehyde	314	19.1	330	460	130	260
Pyrene-1-carbaldehyde	397	9.8	397	470	73	246
9H-Fluorene-2-carbaldehyde	318	34.6	330	409	79	188
6-Dimethylamino-2-naphthaldehyde	377	18.4	396	528	132	173
Anthracene-9-carbaldehyde	408	6.7	410	519	109	106
10-Methyl-anthracene-9-carbaldehyde	425	9.1	399	531	132	26
Phenanthrene-9-carbaldehyde	318	13.2	334	471	137	25
10-Chloro-antharacene-9-carbaldehyde	437	6.0	410	532	122	22
3-(4-Nitro-phenyl)-propenal	308	27.0	397	460	63	9
3-(4-Dimethylamino-phenyl)-propenal	399	41.1	397	494	97	5
4-Quinoline-carbaldehyde	315	3.6	335	430	95	5
5-(4-Dimethylamino-phenyl)-penta-2,4-dienal	409	31.1	418	593	175	5
2-Quinoline-carbaldehyde	301	5.7	346	420	74	4
4-Dimethylamino-benzaldehyde	354	33.7	330	410	80	3
3-Quinoline-carbaldehyde	292	10.6	345	430	85	2
Resorufin	571	64.55	571	581	10	275
7-Hydroxy-4-trifluoromethyl coumarin	341	11.11	356	496	140	276

Note. The data were obtained in 0.1 M sodium phosphate buffer (pH 7.8).

^aMolar absorptivity (10³ M⁻¹ cm⁻¹).

^bEx: optical excitation wavelength.

^cEm_max: maximal emission wavelength.

^dRelative intensity: fluorescent intensity of 2-NA is 100.