Table 1. Photophysical properties of pA (this work) and previously reported FBAs ^a .

Name	One-photon excitation					Two-photon excitation b
	λ Abs (nm)	λ Em (nm)	Φ F c (%)	Brightness, εΦF (M–1 cm–1)		λ Ex (nm)	σ 2  c (GM)	Φ F σ 2 (GM) d
				Monomer	dsDNA e
pA	387	420	66	10 100	1400	780	6.6	5.3
qAN1 (ref. 11)	354	430	18	1700	510	740 f	0.82 f	0.15 f
6-MI25,28	350	431	70	8400 g	1700	700	2.5 39	1.8
6MAP22,26	330	430	39	3300	150	659	3.4 25	1.3
2-AP16,17	303	370	68	4080	50	584	0.2 23	0.14
8-vdA40	290	382	65	8200	200	n.d.	n.d.	n.d.
tC13,14	377	513	13	520	760	800	1.5 h  23	0.32
tCO 15	360	465	30	2700	2000	n.d.	n.d.	n.d.
FDT18	316	434	3	330	n.d.	690	2.1 27	0.063
DMAC41	365	526	3	80	150	n.d.	n.d.	n.d.
thG9,42	321	453	46	1900	310	n.d.	n.d.	n.d.
thU9,43	304	409	41	1300	90 i	690	0.17 27	0.070
TPAU44	332	455	20	2200	n.d.	690	3.8 27	0.76
ADQ45	316	363	4	470	n.d.	690	1.8 27	0.070

^aFor structures and names see Chart S1.

^bTwo-photon excitation determined for FBA monomers.

^cQuantum yield determined in various buffered water solutions at either pH 7.0 or pH 7.5 (top 8 entries) or deionized water (bottom 6 entries).

^dGoeppert-Mayer units, 1 GM = 10^–50 cm⁴ s per photon.

^eAverage over various DNA sequence surroundings. However, in some cases only one sequence was reported.

^fValues from ongoing studies (manuscript in preparation).

^gThe molar absorptivity has not been reported, but is estimated to 12 000 M^–1 cm^–1.46

^hMeasured in the sequence 5′-AATCTCACAGC(tC)TGATCACATTGCTA-3′.

ⁱQuantum yield based on ^thdT dsDNA (2.7%) in the sequence 5′-GCGCGA(^thdT)A(^thdT)A(^thdT)AGGAGC-3′.41