Cyano-Mediated Donor-Acceptor Engineering: A Rational Strategy to Boost Charge Transfer in Carbon Dots for NIR-II...

Area of Science:

• Materials Science
• Biomedical Engineering
• Nanotechnology

Background:

• Carbon dots (CDs) are valuable probes for biomedical imaging.
• Achieving near-infrared emission, particularly in the NIR-II window (1000-1700 nm), remains a significant challenge for CDs.
• Developing CDs with enhanced biocompatibility and targeting capabilities is crucial for clinical translation.

Purpose of the Study:

• To engineer novel carbon dots (CDs) with emission in the second near-infrared window (NIR-II).
• To develop a cyano-mediated donor-acceptor (D-A) strategy for synthesizing NIR-II emissive CDs.
• To enhance the biocompatibility and tumor-targeting ability of the synthesized CDs.

Main Methods:

• Synthesized NIR-II emissive carbon dots (FC-CDs) using benzene-1,2,4,5-tetracarbonitrile and folic acid (FA) via a solvothermal process.
• Employed a cyano-mediated donor-acceptor (D-A) engineering strategy, utilizing the carbon core as a donor and functionalized surface as an acceptor.
• Investigated the D-A structure's role in intramolecular charge transfer and optical bandgap narrowing.

Main Results:

• Successfully synthesized NIR-II emissive carbon dots (FC-CDs) with a D-A configuration.
• Demonstrated that the D-A structure facilitates efficient intramolecular charge transfer and narrows the optical bandgap, enabling NIR-II emission.
• Validated the performance of FC-CDs in various in vivo NIR-II bioimaging applications, including angiography, hepatic ischemia-reperfusion monitoring, and tumor-targeted imaging.

Conclusions:

• The cyano-mediated D-A engineering strategy is effective for designing NIR-II emissive carbon dots.
• FC-CDs exhibit excellent biocompatibility and NIR-II imaging capabilities for in vivo applications.
• This approach provides valuable insights for developing advanced carbon dots for biomedical imaging.