TABLE 1.

1PA, 2PA and emission properties of NIR-II chromophores reported in literature. Solvent and method of 2P properties are also noted for comparison.

Probe	Chemical structure	Solvent	λ1PA max	λem max	Φf	2λ1PA max	λ2PA	σ2 (λ)	σ2 (λ)Φf	Ref.
			(nm)	(nm)		(nm)	(nm)	(GM) a	(GM) a
Xanthenes
Disodium fluorescein (1)		pH11	497	518 c	0.90 c	994	1000	2.7	2.4 b	(Makarov et al., 2008; Mütze et al., 2012)
PhenGreen FL (diacetate, uncomplexed) (2)		PBS	492 c	517 c	0.80 c	984	1074	n.d.	n.d.	(Bestvater et al., 2002)
Rhodamine 6G (3)		MeOH	519 c	546 c	0.95 c	1038	1060	10	9.5 b	(Makarov et al., 2008)
Rhodamine B (4)		MeOH	553 c	627 c	0.70 c	1106	1040	39	27 b	Makarov et al., 2008
Rhodamine 101 (5)		EtOH	570 c	591 c	1.0 c	1140	1060	20	20 b	(Li and She, 2010; Mütze et al., 2012)
Rhodamine 123 (6)		PBS	507	529 c	0.90 c (EtOH)	1014	1090	n.d.	n.d.	(Bestvater et al., 2002)
Alexa Fluor 488 (7)		NaPhos	491	519 c	0.92 c	980	1000	21 b	19	(Bestvater et al., 2002; Anderson and Webb, 2011; Mütze et al., 2012)
Alexa Fluor 546 (8)		PBS	553	573 c	0.79 c	1112	1028	n.d.	n.d.	(Bestvater et al., 2002; Mütze et al., 2012)
Alexa Fluor 568 (9)		PBS	578 c	603 c	0.69 c	1156	1060	n.d.	n.d.	(Mütze et al., 2012)
Alexa Fluor 594 (10)		PBS	594 c	617 c	0.66 c	1180	1074	n.d.	n.d.	(Bestvater et al., 2002; Mütze et al., 2012)
Alexa Fluor 610 (11)		PBS	612 c	628 c	–	1224	1010	n.d.	n.d.	(Mütze et al., 2012)
Alexa Fluor 633 (12)		H2O	632 c	647 c	–	1264	1260	n.d.	<5	(Kobat et al., 2009; Mütze et al., 2012)
MitoTracker Red (13)		PBS	579 c	599 c	0.15 [187]	1158	1133	n.d.	n.d.	(Bestvater et al., 2002)
CellTracker Red (14)		In vitro	585 c	602 c	n.d.	1170	1080	n.d.	n.d.	(Rakhymzhan et al., 2017)
Lissamine Rhodamine-IgG (15)		PBS	570 c	590 c	0.33 [188]	1140	1116	n.d.	n.d.	(Bestvater et al., 2002)
Texas Red-IgG (16)		PBS	596 c	615 c	0.90 c	1192	1150	n.d.	n.d.	(Bestvater et al., 2002)
ATTO 680 (17)		In vitro	681 c	698 c	0.30 c	1362	1260	n.d.	n.d.	(Rakhymzhan et al., 2017)
Nile Red (18)		MeOH	550	636	0.40	1100	1057	104	42	(Hornum et al., 2020)
19		MeOH	554	631	0.43	1108	1055	183	79	(Hornum et al., 2020)
20		MeOH	569	632	0.45	1065	1050	123	55	(Hornum et al., 2020)
21		MeOH	565	638	0.35	1130	1057	232	81	(Hornum et al., 2020)
Polymethines
Cy3-IgG (22)		PBS	548 c	563 c	0.1 c	1096	1032	n.d.	n.d.	(Bestvater et al., 2002)
Cy5 (23)		H2O	646 c	662 c	0.28 c	1292	1220	143 b	≈40	(Kobat et al., 2009)
Cy5.5 (24)		H2O	673 c	691 c	0.21 c	1346	1280	286 b	≈60	(Kobat et al., 2009)
Cy7 (25)		H2O	750 c	773 c	0.30 c	1500	1320	200 b	≈60	(Kobat et al., 2009)
26		DMSO	753	780	0.17	1506	1552	240	41 b	(Berezin et al., 2011)
ICG (27)		DMSO	794	817	0.12	1588	1552	590	71 b	(Berezin et al., 2011)
Cypate (28)		DMSO	796	817	0.13	1592	1552	520	68 b	(Berezin et al., 2011)
29		DMSO	809	829	0.07	1618	1552	900	63 b	(Berezin et al., 2011)
DTTC (30)		DMSO	771 c	800 c	0.80 c	1542	1552	160	128 b	(Berezin et al., 2011)
DODCI (31)		EtOH	582 c	610 c	0.87 c (DMSO)	1164	1060	38	n.d.	(Li and She, 2010)
IR-140 (32)		DMSO	825	≈840	0.06	1640	1552	950	57 b	(Berezin et al., 2011)
33		CH2Cl2	1064	≈1080	0.05	2128	1800	2250	113 b	(Hu et al., 2013)
		CH3CN	1043	≈1065	0.05	2086	1800	1050	53 b
34		EtOH	650	665	n.d.	1300	1180	140	n.d.	(Fu et al., 2007)
35		EtOH	690	704	n.d.	1380	1260	150	n.d.	(Fu et al., 2007)
36		EtOH	770	n.d.	n.d.	1540	1340	60	n.d.	(Fu et al., 2007)
37		EtOH	824	n.d.	n.d.	1648	1480	600	n.d.	(Fu et al., 2007)
Alexa Fluor 647 (38)		H2O	650 c	665 c	0.33 c	1300	1240	133 b	≈44	(Kobat et al., 2009; Mütze et al., 2012)
Alexa Fluor 680 (39)		H2O	679 c	702 c	0.36 c	1358	1280	203 b	≈73	(Kobat et al., 2009)
Alexa Fluor 700 (40)	– d	H2O	702 c	723 c	0.25 c	1404	1320	208 b	≈52	(Kobat et al., 2009)
Alexa Fluor 750 (41)	– d	H2O	753 c	778 c	0.12 c	1506	1320	292 b	≈35	(Kobat et al., 2009)
42		MeOH	532	636	0.44	1064	1064 (900)	23 (570)	10 b	(Pascal et al., 2017)
43		MeOH	573	708	0.33	1146	1146	225	74 b	(Pascal et al., 2017)
44		MeOH	549	673	0.54	1098	1098	137	74 b	(Pascal et al., 2017)
45		Toluene	643	654	0.62	1286	1198	133	82 b	(Ceymann et al., 2016)
46		Toluene	700	714	0.75	1400	1274	100	75 b	(Ceymann et al., 2016)
Styryl 9M (47)		CHCl3	≈625	≈790	0.10 [189]	≈1250	1240	780	78	(Makarov et al., 2008)
FM4-64 (48)		PBS CHCl3 (López-Duarte et al., 2015)	471 564	691 761	n.d. 0.35	942 1128	1047	n.d.	n.d.	(Wokosin et al., 1996a; Nuriya et al., 2016)
TO-PRO-3 (49)		H2O	641 c	657 c	n.d.	1284	1110	n.d.	n.d.	(Smith et al., 2012)
50		THF	562	598	0.07	1124	1070	167	12 b	(Poronik et al., 2012)
51		THF	615	655	0.02	1230	1150	214	4 b	(Poronik et al., 2012)
Porphyrins
52		CCl4	≈770	≈780	n.d.	≈1540	1020 1270	470 48	n.d.	(Makarov et al., 2008)
53		CCl4	≈685	≈700	n.d.	≈1370	1270	13	n.d.	(Makarov et al., 2008)
54		CHCl3	≈525 ≈605 ≈680	710	n.d.	≈1050 ≈1210 ≈1360	≈1040 ≈1220 ≈1360	≈2000 ≈500 ≈200	n.d.	(Nowak-Król et al., 2013)
BODIPYs
LysoTracker Red (55)		PBS	577 c	590 c	0.07	1154	1100	n.d.	n.d.	(Bestvater et al., 2002)
BODIPY-TR (56)		MOPS	589 c	616 c	0.90 c	1178	1060	269 b	242	(Bestvater et al., 2002; Mütze et al., 2012)
IR-07 (57)		CH2Cl2	∼700	750	0.30	∼1400	1310	101	30 b	(Zheng et al., 2009)
58		THF	755	830	0.09	1560	1064	n.d	n.d	(Hu et al., 2020)
Dipoles – Quadrupoles – Miscellaneous
59		NPs (Aq.)	480	678	0.17	960	1040	5.6 × 105	9520	(Alifu et al., 2017)
60		H2O (0.1% DMSO)	530	740	n.d.	1060	1100	n.d.	n.d.	(Zhou et al., 2021)
61		H2O	510	676	0.22	1020	1040	440	97 b	(Massin et al., 2013)
62		CH2Cl2	660	785	0.005	1320	1300	500	2.5 b	(Ricci et al., 2017)
63		CH2Cl2	678	782	0.0005	1356	1300	1400	0.7 b	(Ricci et al., 2017)
64		H2O	≈600	≈725	0.21	≈1200	1200	1.21 × 103	242 b	(Wang et al., 2019b)
65		CHCl3	634	704	0.16	1268	1250	920	147 b	(Li et al., 2012)
66		CHCl3	668	807	0.02	1336	1250	1200	24 b	(Li et al., 2012)
67		CHCl3	1088	1120	0.002	2176	2200	1300	2.6 b	(Ni et al., 2016)
68		CHCl3	1136	1193	0.0002	2272	2300	1500	0.3 b	(Ni et al., 2016)
Propidium iodide (69)		PBS	536 c	617 c	0.20 c (dsDNA bound)	1072	1015	n.d.	n.d.	(Bestvater et al., 2002)
AIEgens and AIEDots
70		NP (aq.)	613	790-810	0.14	1226	1040 1300	16100 1220	2240 b 170 b	(Qi et al., 2018; Liu et al., 2021)
71		NP (aq.) THF	454 ≈451	≈700 ≈699	0.19 n.d.	908	1200 n.d.	76300 n.d.	14500 b n.d.	(Wang et al., 2019c)
72		NP (aq.) H2O/DMSO	≈479 ≈488	≈627 >627	0.06 n.d.	≈960	1040 n.d.	3200 n.d.	192 b n.d.	(Samanta et al., 2021)
73		NP (aq.) Toluene	510 491	709 ≈635	0.14 (solid state)	1020	1000 n.d.	≈520 n.d.	73 b n.d.	(Zheng et al., 2018)
74		NP (aq.) Toluene	538 528	755 ≈636	0.02 (solid state)	1076	1020 n.d.	887 n.d.	18 b n.d.	(Zheng et al., 2018)
75		NP (aq.) THF	522 511	620 532	0.05n.d.	1044	1040 n.d.	2.9 ×106n.d.	1.5 × 105n.d.	(Wang et al., 2015)
Carbon, hybrid and inorganic materials
76	SWCNT-based dopamine sensor	H2O	600–1000	1000–1265 e	0.0023	–	1560	216000	497 b	(Bonis-O'Donnell et al., 2017)
77	Aptamer-modified graphene oxide	H2O	440–720	500–650 f	0.34	–	1120	36000	12240 b	(Pramanik et al., 2014)
78	CDs prepared from urea and citric acid	H2O	540	624	0.06	1080	1200	n.d.	n.d.	(Li et al., 2018)
79	Carbon quantum dots prepared from tris(4-aminophenyl)amine	H2O	592	615	0.84	1184	1100	n.d.	n.d.	(Liu et al., 2020)
80	AuNP with SWCNT	H2O	500–1100	775	n.d.	–	1100	n.d.	n.d.	(Olesiak-Banska et al., 2019)
81	Au25 cluster	H2O	675	830	<0.001	1350	1290	2700	n.d.	(Ramakrishna et al., 2008)
82	PEG-dithiolane AuNC	H2O	355, 670	820	0.08	1370	1100	300	24 b	(Oh et al., 2013)
83	Mn2+-ZnS QD	H2O	318	586	0.65	636	1180	265	172 b	(Subha et al., 2013)
84	PbS/CdS QD	H2O	665	1270	0.18	1330	1550	530	95 b	(Ni et al., 2022)
QD605 (85)	polymer-encapsulated CdSe-ZnS QD	H2O	350–475	605	0.71	–	1000	66200 b	47000	(Larson et al., 2003)
Fluorescent proteins
tdTomato (86)	–	H2O	554 g	581	0.72 b	1108	1050	278	200	(Drobizhev et al. 2011)
tdKatushka2 (87)	–	H2O	588 g	633	0.44 b	1176	1100	143	63	(Drobizhev et al. 2011)
dsRed2 (88)	–	H2O	561 g	587	0.71 b	1126	1050	103	73	(Drobizhev et al. 2011)
HcRFP (89)	–	PBS	592 g	645 g	0.05 g	1184	1160	720 b	36	(Tsai et al., 2006)
mCherry (90)	–	H2O	587 g	610	0.24 b	1174	1080	27	6.4	(Drobizhev et al. 2011)
mBanana (91)	–	H2O	540 g	553	0.69 b	1080	1070	64	44	(Drobizhev et al. 2011)
mStrawberry (92)	–	H2O	574 g	596	0.34 b	1148	1070	20	6.8	(Drobizhev et al. 2011)
mRFP (93)	–	H2O	584 g	611	0.30 b	1168	1080	44	13	(Drobizhev et al. 2011)
TagRFP (94)	–	H2O	555 g	584	0.44 b	1110	1050	95	42	(Drobizhev et al. 2011)
mOrange (95)	–	H2O	548 g	565	0.70 b	1096	1080	67	47	(Drobizhev et al. 2011)
eqFP650 (96)	–	H2O	592 g	646	0.19 b	1184	1112	45	8.5	(Drobizhev et al. 2011)
Katushka (97)	–	H2O	588 g	635	0.35 b	1176	1080	66	23	(Drobizhev et al. 2011)
Katushka2(98)	–	H2O	588 g	633	0.44 b	1176	1140	62	27	(Drobizhev et al. 2011)
mKate (99)	–	pH8	588 g	635	0.27 b	1176	1118	52	14	(Drobizhev et al. 2011)
mKate2 (100)	–	H2O	588 g	633	0.42 b	1176	1140	72	30	(Drobizhev et al. 2011)
mNeptune (101)	–	H2O	600 g	651	0.17 b	1200	1104	70	12	(Drobizhev et al. 2011)
mRaspberry (102)	–	H2O	598 g	625	0.19 b	1196	1118	31	5.8	(Drobizhev et al. 2011)
Neptune (103)	–	H2O	600 g	647	0.22 b	1200	1104	72	16	(Drobizhev et al. 2011)
tdRFP (104)	–	Aq. buffer	584 (Campbell et al., 2002)	579	0.68	1168	1110	20	13.7	(Drobizhev et al. 2011)

^abTwo-photon absorption cross-section value taken at the excitation wavelength λ_2PA reported by the authors in the NIR-II window; note that this may differ from the maximum of the 2PA band. Value extrapolated from the data available and from the formula of the 2P brightness (= σ₂ ^(λ) × Φ_F).

^c1P properties as reported by commercial suppliers, reported in water unless indicated otherwise.

^dChemical structures are propriety and undisclosed.

^eChirality-dependant.

^fExcitation-dependant.

^gProperties extracted from the fluorescent protein database (Available at https://www.fpbase.org/, Accessed on 11/04/2022).