Table 1.
Key properties of genetically encoded sensors for acetylcholine and monoamines.
| Sensors (ref) | Sensitivity (µM) | ΔF/F (%) | SNR (puff) | Kinetics (ms) | Selectivity |
|---|---|---|---|---|---|
| ACh sensors | |||||
| GRABACh2.0 [24] | EC50 = ~1–2 µM | ~90% | ~14 | τon = ~250 ms; τoff = ~700 ms | High |
| GRABACh3.0 [31] | EC50 = ~2 µM | ~280% | – | τon = ~100 ms; τoff = ~900 ms | High |
| iAChSnFR [29] | Kd = ~1 µM | ~1200% | ~50 | kon = 0.62 μM−1s−1; koff = 0.73 s-1 | Kd = ~45 µM (choline) |
| NE sensors | |||||
| GRABNE1m [33] | EC50 = ~2 µM | ~230% | ~75 | τon = ~70 ms; τoff = ~700 ms | EC50 = ~1400 µM (DA) |
| GRABNE1h [33] | EC50 = ~0.1 µM | ~130% | ~10 | τon = ~35 ms; τoff = ~2000 ms | EC50 = ~0.6 µM (DA) |
| 5HT sensors | |||||
| GRAB5HT0.5 [34] | EC50 = ~0.25 µM | ~280% | ~50 | τon = ~60 ms; τoff = ~3300 ms | High |
| GRAB5HT1.0 [34] | EC50 = ~0.02 µM | ~250% | – | τon = ~200 ms; τoff = ~3000 ms | High |
| iSeroSnFR [35] | EC50 = ~1.5 µM Kd = ~350 µM | ~1000% | – | τfast = ~4 ms; τslow = ~100 ms | High |
| DA sensors | |||||
| GRABDA1m [25] | EC50 = ~0.13 µM | ~90% | – | τon = ~60 ms; τoff = ~700 ms | EC50 = ~1.5 µM (NE) |
| GRABDA1h [25] | EC50 = ~0.01 µM | ~90% | – | τon = ~140 ms; τoff = ~2500 ms | EC50 = ~0.1 µM (NE) |
| GRABDA2m [36] | EC50 = ~0.1 µM | ~340% | – | τon = ~40 ms; τoff = ~1300 ms | EC50 = ~1.2 µM (NE) |
| GRABDA2h [36] | EC50 = ~0.03 µM | ~280% | – | τon = ~50 ms; τoff = ~7300 ms | EC50 = ~0.07 µM (NE) |
| rGRABDA1m [36] | EC50 = ~0.1 µM | ~150% | – | τon = ~80 ms; τoff = ~770 ms | EC50 = ~2.2 µM (NE) |
| rGRABDA1h [36] | EC50 = ~0.02 µM | ~100% | – | τon = ~60 ms; τoff = ~2150 ms | EC50 = ~0.06 µM (NE) |
| dLight1.1/1.2 [26, 37] | Kd = ~0.3–0.7 µM | ~300% | – | τon = ~10 ms; τoff = ~100 ms | Kd = ~20 µM (NE) |
| dLight1.3 [26, 37] | Kd = ~2.0 µM | ~900% | – | – | – |
| RdLight1 [41] | Kd = ~2.0 µM | ~250% | – | τon = ~15 ms; τoff = ~400 ms | Kd = ~20–100 µM (NE) |