Multifunctional Fluorescent Material Based Red-emitting Carbon Dots for Cell Imaging and Photodynamic Sterilization

Area of Science:

• Materials Science
• Nanotechnology
• Organic Chemistry

Background:

• Carbon dots (CDs) are versatile nanomaterials with applications in various fields.
• Detailed understanding of the chemical structure of CDs is crucial for optimizing their properties.
• Previous studies often lack in-depth structural characterization of CDs.

Purpose of the Study:

• To synthesize a new type of carbon dot, R1-CDs, using readily available precursors.
• To elucidate the detailed chemical structure of R1-CDs, focusing on hydrogen and carbon atom types.
• To investigate the inheritance of functional groups from precursors to the final carbon dot structure.

Main Methods:

• One-pot hydrothermal synthesis using 1,8-diaminonaphthalene and o-phthalic acid (o-PA).
• Nuclear Magnetic Resonance (NMR) spectroscopy for detailed structural analysis of R1-CDs.
• Analysis of hydrogen (H) and carbon (C) atom types within the graphene sheets of R1-CDs.

Main Results:

• Five distinct types of hydrogen atoms were identified in R1-CDs.
• Eighteen types of carbon atoms were observed, including 8 quaternary and 10 tertiary carbon atoms.
• Functional groups (-COOH and -NH2) from the precursors were not found at the edges or defect sites of the R1-CDs graphene sheet.

Conclusions:

• This study provides unprecedented detail on the chemical structure of carbon dots.
• The findings offer a generalizable concept for fabricating CDs by selecting specific precursors.
• NMR spectroscopy is highlighted as a powerful tool for advancing carbon dot chemistry.