Table 2.

Photophysical properties of the tested genetically encoded biosensors and their aY-modified variants.

Biosensor	Analytical target	λex a (nm)	λem b (nm)	Dynamic Range c (%)	εd (mM−1 •cm−1)		φ e
					−	+	−	+
G-GECO1 34	Ca2+	497	512	1,983	4.7	68.1	0.26	0.38
aY-G-GECO1	Ca2+	528	594	1,566	7.7	79.9	0.14	0.22
ZnGreen1 35	Zn2+	474	500	2,531	24.8	1.3	0.48	0.35
aY-ZnGreen1	Zn2+	520	585	915	34.7	4.8	0.28	0.20
iGluSnFR 36	glutamate	488	510	257	9.6	32.6	0.58	0.60
aY-iGluSnFR	glutamate	528	600	270	12.2	42.7	0.46	0.49
iGABASnFR 37	GABA	502	513	143	NDf	NDf	NDf	NDf
aY-GABASnFR	GABA	541	602	92	NDf	NDf	NDf	NDf
dLight1.2 38	dopamine	496	513	194	NDf	NDf	NDf	NDf
aY-dLight1.2	dopamine	545	603	117	NDf	NDf	NDf	NDf
SoNar 39	NAD+/NADH	497	512	257 [2,532]g	7.6	23.0	0.44	0.51
aY-SoNar	NAD+/NADH	544	604	426 [2,656]g	6.5	28.6	0.29	0.35
iNap1 40	NADPH	497	513	82 [273]g	22.6	13.1	0.50	0.43
aY-iNap1	NADPH	545	604	614 [11,735]g	27.6	4.4	0.41	0.36
PercevalHR 41	ATP	498	513	155 [364]g	14.6	35.6	0.28	0.28
aY-PercevalHR	ATP	545	604	117 [650]g	18.4	40.5	0.21	0.21
iATPSnFR1.1 42	ATP	493	513	106	22.6	43.9	0.36	0.37
aY-iATPSnFR1.1	ATP	541	608	75	29.1	50.9	0.28	0.28

^awavelength of the excitation peak near 490 and 540 nm for green and aY-modified, red fluorescent biosensors, respectively.

^bwavelength of the emission peak.

^cunless otherwise specified, dynamic range is defined as the intensiometric change (ΔF/F_min) around emission peaks in the presence of 480 and 540 nm excitation for green and aY-modified, red fluorescent biosensors, respectively.

^dextinction coefficient in the presence (+) or absence (−) of the corresponding analyte. For SoNar and aY-SoNar, presented are values with NAD⁺ (+) or NADH (−).

^equantum yield.

^fnot determined.

^gin square brackets are dynamic ranges (R_max/R_min) of the sensors operated in the excitation-ratiometric mode; defined as the ratio of the intensity ratios at two excitation peak wavelengths.