Practical Three-Minute Synthesis of Acid-Coated Fluorescent Carbon Dots with Tuneable Core Structure

Area of Science:

• Materials Science
• Nanotechnology
• Biomedical Engineering

Background:

• Fluorescent carbon dots (FCDs) are nanomaterials with diverse applications.
• Developing efficient synthesis methods for functionalized FCDs remains a challenge.
• Carboxylic acid groups enhance FCDs' utility in sensing and bioimaging.

Purpose of the Study:

• To develop a rapid and efficient synthesis for carboxylic acid-decorated fluorescent carbon dots (COOH-FCDs).
• To investigate the formation mechanism and tuneable morphology of these COOH-FCDs.
• To evaluate the potential of COOH-FCDs as selective sensors and non-toxic bioimaging agents.

Main Methods:

• One-pot synthesis of COOH-FCDs in three minutes.
• Surface passivation agent variation to control core morphology.
• Mechanism investigation using spectroscopic analysis to identify key motifs.
• Testing COOH-FCDs for selective sensing of Fe³⁺ and hemin.
• Assessing cytotoxicity and evaluating COOH-FCDs in cancer cell bioimaging.

Main Results:

• Successful one-pot, three-minute synthesis of COOH-FCDs.
• Tuneable core morphology achieved by altering surface passivating agents.
• Identified pyrazine and polyhydroxyl aromatic motifs from glucosamine degradation.
• Demonstrated selective sensing of Fe³⁺ and hemin with high sensitivity.
• Confirmed non-toxicity and effective fluorescent bioimaging of cancer cells.

Conclusions:

• A rapid and versatile method for synthesizing COOH-FCDs was established.
• The synthesized COOH-FCDs exhibit excellent selectivity as Fe³⁺ and hemin sensors.
• COOH-FCDs are promising non-toxic fluorescent probes for cancer cell bioimaging.