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