Chitosan functionalized nitrogen-doped carbon dot nanocomposites: a turn-on sensor for fluoride detection

Area of Science:

• Environmental Science
• Analytical Chemistry
• Materials Science

Background:

• Fluoride is essential for dental and bone health but toxic in excess.
• Accurate fluoride monitoring in water is crucial due to health risks.
• Developing sensitive aqueous-phase fluorescent probes for fluoride is challenging.

Purpose of the Study:

• To develop a novel, eco-friendly fluorescent probe for selective fluoride detection.
• To investigate the mechanism of fluoride detection using the developed probe.
• To assess the probe's performance in real-world samples.

Main Methods:

• Synthesis of chitosan-functionalized N-doped carbon dots (N-CDs@C).
• Characterization of N-CDs@C and evaluation of its fluorescence response to fluoride.
• Investigation of interaction mechanisms (hydrogen bonding, electrostatic interaction).
• Determination of selectivity, anti-interference, and detection limit.

Main Results:

• N-CDs@C demonstrated a "turn-on" fluorescence response to fluoride ions.
• The probe showed high selectivity and anti-interference capabilities.
• A low detection limit of 0.01 μM was achieved within a 0.12-0.50 μM linear range.
• Successful application in real samples (toothpaste, tap water) with high recovery rates (98.67-99.27%).

Conclusions:

• Chitosan-functionalized N-doped carbon dots (N-CDs@C) are effective fluorescent probes for fluoride detection.
• The developed sensor is environmentally friendly, cost-effective, and highly sensitive.
• This probe offers a promising tool for routine monitoring of fluoride levels in aqueous media.