Multicolour Emission States from Charge Transfer between Carbon Dots and Surface Molecules

Area of Science:

• Materials Science
• Nanotechnology
• Photochemistry

Background:

• Carbon dots (CDs) are fluorescent nanomaterials with tunable optical properties.
• Controlling charge transfer is key to modulating the emissive states of carbon dots.
• Functionalization of carbon dots with organic molecules offers a pathway to tailor their photoluminescence.

Purpose of the Study:

• To tune the emissive states and optical properties of carbon dots.
• To investigate the role of charge transfer in modifying carbon dot emission.
• To explore the potential of functionalized carbon dots for bio-conjugation.

Main Methods:

• Carbon dots were synthesized and coupled with molecules containing benzene rings and heteroatom substituents via amino-carboxylic bonds.
• Charge transfer was facilitated from carbon dots to the lowest unoccupied molecular orbital (LUMO) of grafted molecules.
• Optical properties and emission colors were analyzed by varying heteroatom substituents.

Main Results:

• The charge transfer process effectively tuned the emissive states of carbon dots.
• New radiative recombination pathways were established through photo-excited electron transfer.
• Varied heteroatom substituents led to distinct optical properties and emission colors of the carbon dots.

Conclusions:

• Controlling charge transfer via molecular functionalization is a viable strategy for tuning carbon dot emission.
• The developed method allows for precise control over the optical properties of carbon dots.
• This approach provides a versatile platform for conjugating carbon dots with drugs and biomolecules, enabling new applications.