Carbon Nanodots

Discovered by accident while researchers were purifying carbon nanotubes in 2004, carbon nanodots (CNDs, or simply C-dots) are nanoparticles with sizes below 10 nm. Like fullerene, carbon nanotubes, and graphene, carbon nanodots are surface‐passivated carbonaceous quantum dots. They are typically composed of carbon, oxygen, nitrogen and hydrogen.

The relative amount present of each of these elements depends on the synthesis process used to create the carbon nanodots. Carbon dots can be synthesised from different approaches featuring bright fluorescent emission tuneable across the visible range, high water solubility with rich hydrophilic surface groups, biocompatibility, high sensitivity to the external environment, and marked electron donating and accepting capabilities.

Compared with other semiconductor nanodots with heavy metal cores, carbon nanodots have a number of distinct benefits including chemical inertness, low toxicity, ease of functionalization and resistance to photobleaching. Carbon nanodots are versatile and can be used in a wide range of technologies, such as bioimaging, photocatalysis, sensing, lasers, LED, and energy conversion/storage devices.

Applications of Carbon Nanodots

For their excellent optical properties, high biocompatibility and environmentally low toxicity, carbon dots find applications in biosensing, drug delivery, bioimaging, light emitting diode (LED), logic gates and energy storage devices.

• Biosensing/bioimaging
• Drug delivery
• Light-emitting diodes (LED)
• Logic gates
• Photocatlysis
• Energy and charge transfer devides

Literature and Reviews

• A Biocompatible Fluorescent Ink Based on Water-Soluble Luminescent Carbon Nanodots, S. Qu et al., Angew. Chem. Int. Ed. 2012, 51, 12215 –12218 (2012); DOI: 10.1002/anie.201206791.
• Carbon Nanodots: Toward a Comprehensive Understanding of Their Photoluminescence, V. Strauss et al., J. Am. Chem. Soc., 136, 17308−17316 (2014); DOI: 10.1021/ja510183c.
• Carbon Nanodots: A Review—From the Current Understanding of the Fundamental Photophysics to the Full Control of the Optical Response, A. Sciortino et al., C - J. Carb. Res., 2018, 4(4), 67; DOI: 10.3390/c4040067.
• Novel properties and applications of carbon nanodots, L. Xiao et al., Nanoscale Horiz.,3, 565-597 (2018); DOI: 0.1039/C8NH00106E.
• Synthesis and analytical applications of photoluminescent carbon nanodots, P-C. Hsu et al., Green Chem., 14, 917 (2012); 10.1039/c2gc16451e.
• 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.
• Carbon nanodots: synthesis, properties and applications, H. Li et al., J. Mater. Chem.,22, 24230-24253 (2012); DOI: 10.1039/C2JM34690G.