Carbon dot@metal-organic frameworks with aggregation-induced emission for visual detection of ascorbic acid

Area of Science:

• Materials Science
• Analytical Chemistry
• Nanotechnology

Background:

• Current fluorescence-based sensors for ascorbic acid (AA) lack specificity and sensitivity for in-situ detection.
• Existing "turn-on" or "turn-off" sensor designs are insufficient for precise AA responses.

Purpose of the Study:

• To develop a sensitive multicolor-switching luminescent sensor for specific ascorbic acid (AA) detection.
• To create ratiometric luminescent probes for enhanced in-situ analysis of AA.

Main Methods:

• Encapsulation of carbon dots (CDs) into an aggregation-induced luminescence metal-organic framework (AIE-MOF).
• Utilized fluorescence resonance energy transfer (FRET) mechanism between CDs and AIE-MOF for signal transduction.
• Developed fluorescent test paper for visual, on-site AA detection.

Main Results:

• The CDs@AIE-MOF probe exhibited sensitive and specific detection of AA with a linear range of 0.02-255 μM and a detection limit of 6.6 nM.
• A distinct visual luminescence color change from orange-red to yellow to green was observed during AA sensing.
• The FRET inhibition mechanism allowed for the restoration of AIE-MOF fluorescence upon AA binding.

Conclusions:

• The developed CDs@AIE-MOF probe offers a highly sensitive and selective method for AA detection.
• The strategy enables visual, on-site detection of AA using fluorescent test paper.
• This approach expands possibilities for dual-emission fluorescent probes in visual sensing applications.