Table 3. Ratiometric Small-Molecule Zn2+ Sensors.
| excitation |
emission |
brightnessb |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| name | λfree (nm) | εfreea | λbound (nm) | εbounda | λfree (nm) | φfree | λbound (nm) | φbound | free | bound | KD (M) | DR (Rmax/Rmin) | ref |
| FuraZin | 378 | ND | 330 | ND | 510 | ND | 510 | ND | ND | ND | 2.1 × 10–6 | 9 | (123) |
| IndoZin | 350 | ND | 350 | ND | 480 | ND | 395 | ND | ND | ND | 3.0 × 10–6 | ND | (123) |
| ZnAF-R1 | 359 | ND | 329 | ND | 532 | 0.088 | 528 | 0.031 | ND | 10.199 | 7.9 × 10–10 | ND | (151a) |
| ZnAF-R2 | 365 | ND | 335 | ND | 495 | 0.17 | 495 | 0.1 | ND | 33.5 | 2.8 × 10–9 | 7 | (151a) |
| Zinbo-5 | 337 | ND | 376 | ND | 407 | 0.02 | 443 | 0.1 | ND | 37.6 | 2.2 × 10–9 | 33 | (150) |
| ZNP1 | 503/539 | 7.2/6.7 | 547 | ND | 528/604 | 0.02 | 624 | 0.05 | ND | ND | 5.5 × 10–10 | 17.8 | (151b) |
| RF3 | 514 | 9.5 | 495 | 4.4 | 540 | 0.62 | 523 | 0.52 | 5.89 | 257.4 | 2.2 × 10–5 | 2.4 | (131) |
| DIPCY | 627 | 70 | 671 | 85 | 758 | 0.02 | 765 | 0.02 | 1.4 | 13.42 | 9.8 × 10–8 | 1.5 | (151c) |
| 4-Zn | 400 | 16.9 | 431 | ND | 484 | 0.64 | 505 | ND | 10816 | ND | 5.0 × 10–7 | 17.8 | (139) |
| CZ1 | 445 | 37.2 | 445 | 41 | 488 | 0.01 | 488 | 0.01 | 0.372 | 4.45 | 2.5 × 10–10 | 8 | (152a) |
| 505 | 38.6 | 505 | 38.1 | 534 | 0.02 | 534 | 0.04 | 0.772 | 20.2 | ||||
| CZ2 | 450 | 26 | 448 | 26.6 | 490 | 0.01 | 490 | 0.02 | 0.26 | 8.96 | 2.5 × 10–10 | 4 | (152b) |
| 526 | 22.4 | 521 | 24.3 | 535 | 0.01 | 535 | 0.04 | 0.224 | 20.84 | ||||
a
Molar extinction coefficients given as ε/103 M–1 cm–1.
b
Brightness is defined as the product of the molar extinction coefficient and the quantum yield (ε × φ). ND, not determined.