Graphene Quantum Dots

Graphene quantum dots (GQDs), CAS number 7440-44-0, are referred to as small fragments of graphene with a two-dimensional lateral size less than 100 nm. However, majority of as prepared graphene quantum dots are multiple layers of graphene of sizes less than 10 nm, containing both hydrogen and oxygen. The difference between GQDs and CQDs is that GQDS are sp² hybridized while CQDs are sp³ hybridized. The photoluminescence of CQDs is produced by surface passivation while GQDS is by quantum confinement.

The photoluminescent emission and excitation wavelengths of GQDs can be tuned by controlling the size of the nanoparticles, altering the surface properties or by the introduction of dopants into the carbon lattice. Due to large surface area and the oxygen-containing groups on the surface providing active sites for drug molecules carrying and loading, graphene quantum dots have relatively good biocompatibility in biological medicine than graphene or graphene oxides.

Being biocompatible, non-toxic, photo-stable, water-soluble, low cost and environmentally friendly, GQDs have shown significant potential in numerous fields such as energy devices, catalysis, sensing, photodynamic and photothermal therapy, drug delivery, and bioimaging.

Environmentally friendly

Eco friendly and non-toxic

Large surface area

Providing active sites

Low Cost

Low Cost Graphene Quantum Dots

Various Applications

Biosensing/bioimaging, Catalysis & Batteries

Applications of Graphene Quantum Dots

With high biocompatibility, photostability, environmentally low toxicity and low cost, graphene quantum dots find applications in drug medicine delivery, energy devices sensing and bioimaging.

• Biosensing/bioimaging
• Drug delivery
• Photothermal therapy
• Catalysis
• Batteries
• Organic Photovoltaic devices

Literature and Reviews

• Graphene Quantum Dots and Their Applications in Bioimaging, Biosensing, and Therapy, S. Chung et al., Adv. Mater., 33 (22), 1904362 (2021); DOI: 10.1002/adma.201904362.
  
• Synthesis, Applications, and Prospects of Graphene Quantum Dots: A Comprehensive Review, A. Ghaffarkhah et al., Small, 18 (2), 2102683 (2022); DOI: 10.1002/smll.202102683.
  
• Bottom-Up Fabrication of Photoluminescent Graphene Quantum Dots with Uniform Morphology, R. Liu et al., J. Am. Chem. Soc., 133 (39), 15221–15223 (2011); DOI: 10.1021/ja204953k.
  
• Glowing Graphene Quantum Dots and Carbon Dots: Properties, Syntheses, and Biological Applications, X. Zheng et al., Small, 11 (14), 1620-1636 (2015); DOI: 10.1002/smll.201402648.
  
• Recent Advances on Graphene Quantum Dots: From Chemistry and Physics to Applications, Adv. Mater., 31 (21), 1808283 (2019); DOI: 10.1002/adma.201808283.
  
• Graphene Quantum Dots Derived from Carbon Fibers, J. Peng et al., Nano Lett., 12 (2), 844–849 (2012); DOI: 10.1021/nl2038979.
  
• The photoluminescence mechanism in carbon dots (graphene quantum dots, carbon nanodots, and polymer dots): current state and future perspective, S. Zhu et al., Nano Res., 8, 355–381 (2015); DOI: 10.1007/s12274-014-0644-3.
  
• Investigating the surface state of graphene quantum dots, S. Zhu et al., Nanoscale, 7, 7927-7933 (2015); DOI: 10.1039/C5NR01178G.
  
• Coal as an abundant source of graphene quantum dots, R. Ye et al., Nat. Commun., 4, 2943 (2013); DOI: 10.1038/ncomms3943.
  
• Luminscent Graphene Quantum Dots for Organic Photovoltaic Devices, V. Gupta et al., J. Am. Chem. Soc., 133 (26), 9960–9963 (2011); DOI: 10.1021/ja2036749.
  
• Fluorescence and Sensing Applications of Graphene Oxide and Graphene Quantum Dots: A Review, P. Zheng et al., Chem. 12 (18), 2343-2353 (2017); DOI: 10.1002/asia.201700814.
  
• Carbon and Graphene Quantum Dots for Optoelectronic and Energy Devices: A Review, X. Li et al., Adv. Funct. Mater., 25 (31), 4929-4947 (2015); DOI: 10.1002/adfm.201501250.
  
• Synthesis and applications of graphene quantum dots: a review, W. Chen et al., Nanotechnol. Rev., 7(2): 157–185 (2018); DOI: 10.1515/ntrev-2017-0199.