Table 1

Examples of synthesized quantum dots with their precursors, sizes and their respective synthesis processes.

Quantum dot Synthesis process Size (nm) Medium precursor Application References
CdSe Bottom-up approach (hot-solution decomposition process) ~6 nm Me2Cd, Se, TBP, TOPO, HPA FRET Peng et al. [32]
Manna et al. [33]
CdSe/ZnS Bottom-up approach (hot-solution decomposition process) 4.5–5 nm Me2Cd, Se, TOP, TOPO, HDA, (TMS)2S, Me2Zn FRET Hikmet et al. [29]
PbS Bottom-up approach (hot-solution decomposition process) 5 nm PbO, OA, (TMS)2S Photo-electronic devices Bakueva et al. [35]
ZnSe/ZnS Vapour-phase method 1–1.9 nm TOPO, diethyl zinc, L hexa-methyl-disilathiane, TBP FRET, LEDs Kim et al. [36, 65]
CdSe/ZnSe/ZnS Hot solvent mixture (bottom-up approach) ~8.6 nm TOPO, diethyl zinc, L hexa-methyldisilathiane, TBP, CdO:Se molar ratio of 1:5 Intra-cellular pH sensors Liu et al. [37]
C-QDs (Carbon quantum dots) Hydrothermal (green material used as source) 4–6 nm Banana peel waste Bio imaging Atchudan et al. [38]
C-QDs (COC dots), sulfur doped with hydrophilic groups at the surface Ultrasonication (other methods) 1–4 nm Waste chimney oil Sensors, bio-labeling, and ink Das et al. [39]
C-QDs (Carbon quantum dots) Pyrolysis (heat synthesis) 6 nm Finger-milletragi, CaCl2·2H2O, CuSO4·5H2O, Ni(NO3)2·6H2O, Mn(NO3)2.6H2O, MgCl2·6H2O Biosensor Murugan et al. [40, 60]
Graphene QDs (colloidal) Modified hummers method (heat and ultrasonic treatment) 2.9–3.6 nm Graphene oxide sheets HeLa cell line Cell nucleus (bio-imaging)/cellular imaging Pan et al. [41, 62]
Boron-doped graphene quantum dots Hydrothermal process (modified hummers process) 3–7 nm Graphite rods, 0.1 M borax Stem-cell imaging (bio-imaging), cellular imaging Fan et al. [42, 43]