Ultrasensitive fluorescent sensing platform based on N, Zr co-doped carbon dots: Cr(VI) detection and solid-state...

Area of Science:

• Materials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Carbon dots (CDs) are versatile nanomaterials with tunable photoluminescence.
• Nitrogen doping enhances the properties of carbon dots for various applications.
• Controlling the nitrogen species (graphitic vs. amino) is crucial for optimizing CD performance.

Purpose of the Study:

• To engineer nitrogen-doped carbon dots (N, Zr co-doped CDs) with tailored graphitic N/amino N ratios.
• To develop an ultrasensitive fluorescent probe for Cr(VI) detection.
• To explore the application of these CDs in latent fingerprint visualization and composite materials.

Main Methods:

• Synthesis of N, Zr co-doped carbon dots using different nitrogen precursors (ethylenediamine vs. urea).
• Characterization of carbon dots' structure, composition, and photoluminescence properties.
• Fabrication of a CDs-2@MOF composite material and evaluation of its functionalities.

Main Results:

• Ethylenediamine-derived CDs (CDs-2) showed a higher graphitic N content, enhanced photoluminescence, and an electron-deficient structure.
• An ultrasensitive fluorescent probe for Cr(VI) was developed with a low detection limit (2.208 μM) based on synergistic quenching.
• Real-time fluorescent visualization of latent fingerprints and dual functionality in LEDs were achieved with the CDs-2@MOF composite.

Conclusions:

• Defect engineering in carbon dots by controlling the graphitic N/amino N ratio is a viable strategy for developing multifunctional probes.
• The synthesized CDs and CDs-2@MOF composite show promise for sensitive environmental monitoring and advanced material applications.
• This work provides new insights into designing high-performance carbon dot-based materials.