Table 2.

Imaging-supported sensing applications using FL CDs.

Precursors/forms	FL color	Applied Ex/Em (nm)	Microscopic	Application	Biotarget	Ref.
Ascorbic acid, L-arginine	Green	750/380–495	Two-photon CLSM	Imaging of tissues	Pigskin tissue	[120]
	Red	750/500–650		Sensing of Fe3+	Fibroblast skin cells
Abelmoschus manihot	Blue	330/410	FM	Sensing of 2,4,6-trinitrophenol (TNT)	Hela	[121]
Casein	Blue	383/446	CLSM	Sensing of Hg2+, biothiols	HeLa	[122]
Catechol, triethylene tetramine	Green	415/515	CLSM	Sensing of Fe3+, ascorbic acid (AA)	MCF-7	[123]
p-phenylenediamine, ammonia	Green	361/515	CLSM	Sensing of CrVI, TNT, and AA	SMMC7721	[124]
p-aminosalicylic acid, ethyleneglycol dimethacrylate	Green	390/520	FM	Sensing of Fe3+	BT474	[125]
Glycerol, DAMO	Blue	350/442	CLSM	Sensing of Fe3+	Zebrafish, Hela,	[126]
				Cancer/normal cell differentiation	A549, Hep G2/ AT II, L02
Glutaraldehyde	Blue	440/–	CLSM	Sensing of microRNA-21	MCF-7	[127]
nitro benzaldehyde		360/–
benzaldehyde		360/–
CDs-chitosan
White pepper, H2N-PEG-NH2	Green	420/525–550	CLSM	Sensing of coenzyme A	HeLa	[128]
	Red	420/>560
CA, PEI	Blue	350/450	CLSM	Sensing of H2O2	HeLa	[129]
CQD-AuNC	Red	550/620
CA, melamine	Blue	360/440	CLSM	Sensing of Hg2+, glutathione (GSH)	BHK	[130]
o-phenylenediamine	Green	488/–	CLSM	Sensing of atrazine	E. coli, S. aureus	[131]
2,3-diaminophenazine	Green	495/530	CLSM	Sensing of NAD+	A375 cells	[132]
Fungus fibers	Blue	360/440	FM	Sensing of tetracyclines	HepG2	[133]
CA, EDA	Blue	345/453	CLSM	Sensing of CA125	OVCAR-3	[134]
CD-aptamer
CA, L-cysteine	Blue	355/425	FM	Sensing of testosterone	293T	[135]
β-CD-CDs
L-tartaric acid, triethylenetetramine	Blue	350/425	CLSM	Sensing of metronidazole	MCF-7	[136]
CA	Blue	380/450	FM	Sensing of cathepsin B	HeLa	[137]
AS1411-Ce6-CQDs
m-aminophenol	Yellow–green	450/520	CLSM	Sensing of selenol	L929	[138]
CD-DNS
Food grade agave nectar, α-methoxy-ω-phosphate PEG	Red	430/600	In vivo imaging system	Imaging of hydroxyapatite-targeted bone	Athymic nude mice	[119]
CA, EDA	Blue, yellow	360/440, 565	CLSM	Sensing of thioredoxin reductase	MCF-7, HeLa cells	[139]
Biotin-CD-Naph
Neutral red, triethylamine	Yellow	478/532, 618	CLSM	Sensing of Ag+, GSH	SMMC7721	[140]
Chestnut, onion	Blue	370/440	CLSM	Sensing of coenzyme A	T24	[141]
Aconitic acid, tryptophan	Blue	370/455	CLSM	Sensing of cytochrome c	HepG-2, zebrafish	[142]
FO-Pte, FO-PSe	Green	800/400–600	Two-photon CLSM	Sensing of superoxide anion	Hela, A549	[143]
					Breast tumor tissue
EDTA-2Na, CuCl2	Blue	370/480	CLSM	Sensing of H2S	H3122	[144]
CA	Blue	405/470	CLSM	Sensing of Fe3+, AA	HepG2, zebrafish, liver ischemia tissue	[145]
CDs-DB	Red	405/450–550
CA, phenosafranine,	Orange	525/600	CLSM	Sensing of nitrite	A549	[146]
HAuCl4, GSH, and glucose	Green	405/495–575	FM	Sensing of SKBR3 exosomes	HeLa	[147]
PEI-GCDs-Ab
CA, 2,3-Phenazinediamine	Yellow	380/568	FM	Sensing of Ag+, GSH	H1299	[148]
CA, urea, and triethylenetetramine	Blue	380/470	CLSM	Sensing of Cu2+, GSH	Yeast	[116]
CA, methionine	Blue	350/420	FM	Sensing of Al3+	HUVEC	[149]
	Green	350/502
Dunaliella salina	Green	340/415	FM	Imaging of cells	HEK-293	[150]
	Red			Sensing of Hg2+, Cr6+
Alkali lignin, EDA, and formaldehyde	Blue	405/–	CLSM	Imaging of cells	RAW264.7	[151]
	Green	488/–		Sensing of Fe3+
	Red	558/–
Ocimum sanctum	Blue	330–385/–	FM	Imaging of cells	MDA-MB 468	[152]
	Green	450−480/–		Sensing of Pb2+
	Red	510–550/–
Banana plant	Blue	408/–	CLSM	Sensing of Fe3+	Hela, MCF-7	[153]
	Green	488/–
	Red	561/–
Ganoderma lucidum spores	Blue	405/–	CLSM	Sensing of Fe3+	MIHA	[154]
	Green	488/–
	Red	559/–
Phthalic acid, EDA, and H3PO4	Blue	405/422	CLSM	Imaging of cells	SMMC-7721	[155]
	Green	488/500		Sensing of Mn7+
	Red	543/650
Phthalocyanine	Green	780/520	Two-photon CLSM	Imaging of cells	MCF-7	[118]
	Red	850–890/600		Sensing of Fe3+
Magnolia liliiflora	Blue	405/–	CLSM	Sensing of Fe3+	Clone 9 hepatocytes	[156]
	Green	488/–
	Red	555/–
Sweet potato	Blue	330–388/405	CLSM	Imaging of cells	Hela, HepG2	[157]
	Green	450–480/–		Sensing of Fe3+
	Red	510–550/–
Glucose, octadecylamine, and octadecene	Green	425/485	CLSM	Sensing of Cu2+	HepG2, HL-7702	[158]
HCD-based micelle	Red	425/655
Syringa obtata Lindl	Blue	340/425	CLSM	Sensing of Fe3+	MCF-7	[159]
	Green	450/520
Black soya beans	Blue	405/–	CLSM	Imaging of cells	SMMC-7721	[160]
	Green	488/–		Sensing of Fe3+
	Red	543/–
Aspartame	Blue	405/420–480	CLSM	Imaging of cells	SGC-7901	[161]
	Green	405/500–560		Sensing of Fe3+
	Red	555/600–700
o-phenylenediamine, 4,5-difluoro-1,2-benzenediamine, and tartaric acid	Green	480/600	FM	Imaging of cells	HEK 293T, NIH 3T3,	[162]
	Red	540/550		Sensing of Ag+	COS-7, HepG2, and B16F10
Aminosalicylic acid	Green	405/–	CLSM	Sensing of Fe3+	H1299	[163]
	Yellow	488/–
	Red	542/–
CA, thiourea	Blue	405/450	FM	Imaging of cells	MiaPaCa-2	[164]
				Sensing of Fe3+
L-glutamic acid, EDA	Blue	360/459	CLSM	Imaging of fungi	C. gloeosporioides	[165]
				Sensing of Fe3+
m-phenylenediamine, diethylenetriaminepenta (methylenephosphonic acid)	Green	440/510	CLSM	Imaging of cells	A549, KB	[166]
				Sensing of Fe3+
CA, diethylenetriamine	Blue	391/438	FM	Sensing of Co2+	HeLa	[167]
Osmanthus fragrans	Blue	340/410	FM	Sensing of Fe3+, AA	A549	[168]
CA, methylamine hydrochloride, and lanthanum	Green	420/510	FM	Sensing of Fe3+	HeLa	[169]
chloride heptahydrate
Tetraphenylporphyrin-Mn, CA	Blue	330–385/–	FM	Sensing of Fe3+	HeLa, zebrafish	[170]
	Green	400–440/–
	Red	510–550/–
P-phenylenediamine	Orange	566/590	CLSM	Sensing of intracellular pH	SMMC7721	[171]
CA, 1,4-butanediamine	Blue	380/443	CLSM	Sensing of intracellular pH	Pholiota adipose fungi	[172]
RhB-AB-CDs	Red	400/580
p-phenylenediamine	Red	488/550–650	CLSM	Imaging of cells	HepG2, HL-7702	[173]
				Sensing of intracellular polarity
Ascorbic acid	Yellow	405/415–550	CLSM	Imaging of nucleolus	293T	[174]
				Sensing of temperature