Table 1.

Summary of Fluorescent FA probes

Probe	λex (nm)	λem (nm)	Response to FA in vitro	Biological Application
aza-Cope-based probes
FAP-1 [49]	645	662	8-fold turn-on to 0.1 mM FA (1 h, 20 mM PBS)	Cells (HEK293T, MCF7)
FP1 [50]	620	649	7-fold turn-on to 0.5 mM FA (3 h, PBS)	Cells (HEK293T.NS1)
RFFP [51]	318	359 (451 post-FA)	53-fold ratio change to 3 mM FA (4 h, 25 mM PBS/1% acetone)	Cells (HeLa)
AENO [52]	319	513	ca. 110-fold turn-on to 5 mM FA (3 h, 10 mM PBS/20% DMF)	Cells (HeLa)
FATP1 [53]	390	526	25-fold turn-on to 0.2 mM FA (3 h, 20 mM PBS/5% DMSO)	Cells (HEK293T, MCF7), Tissue (liver)
TPNF [54]	350	510	20-fold turn-on to 5 mM FA (3 h, 10 mM PBS/0.5% DMSO)	Cells (HeLa), Zebrafish
FAP573 [55]	573	585	4.2-fold turn-on to 0.1 mM FA (2 h, 20 mM PBS/0.1% DMSO)	Cells (HEK293T, HAP1, MEF)
Formimine based probes
Na-FA [58]	440	543	900-fold turn-on to 0.1 mM FA (30 min, 10 mMPBS/l% DMSO)	Cells (HeLa), Tissue (liver)
Na-FA-Lyso [60]	440	541	350-fold turn-on to 0.2 mM FA (30 min, 10 mM PBS/1% DMSO)	Cells (HeLa)
1 [59]	428	541	140-fold turn-on to 0.5 mM FA (8 min, 10 mM PBS/1% DMSO)	Cells (4T-1, 3T3), Tissue (tumor)
Aminal based probes
R6-FA [61]	530	560	7.4-fold turn-on to 0.01 mM FA (10 sec, 25 mM PBS/50% DMF)	Cells (HeLa)
L [62]	520	620	ca. 7-fold turn-on to 10 mMFA (10 mM Tris/30%EtOH)	Cells (L929)