Multi-sensing function integrated nitrogen-doped fluorescent carbon dots as the platform toward multi-mode detection...

Area of Science:

• Materials Science
• Analytical Chemistry
• Biomedical Engineering

Background:

• Developing novel nanomaterials for sensitive and selective detection of analytes is crucial.
• Carbon dots (CDs) are emerging as promising fluorescent probes due to their unique optical properties and biocompatibility.
• Nitrogen doping can further enhance the photoluminescence and sensing capabilities of carbon dots.

Purpose of the Study:

• To synthesize nitrogen-doped carbon dots (N-CDs) for multi-mode sensing.
• To investigate the sensing mechanisms for chromium(VI) [Cr(VI)], 2,4,6-trinitrophenol (TNP), and ascorbic acid (AA).
• To evaluate the potential of N-CDs for bioimaging applications.

Main Methods:

• One-pot synthesis of N-CDs using p-phenylenediamine and ammonia.
• Characterization of N-CDs using Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, and fluorescence spectroscopy.
• Development of a multi-mode sensing strategy based on fluorescence quenching and redox reactions.

Main Results:

• N-CDs exhibited green fluorescent emission with good photostability.
• Cr(VI) and TNP caused fluorescence quenching of N-CDs via the internal filtration effect.
• A sequential sensing approach was developed for Cr(VI) and AA detection.
• N-CDs demonstrated low toxicity and biocompatibility, enabling successful bioimaging in SMMC7721 cells.

Conclusions:

• N-CDs serve as an effective photoluminescent platform for the multi-mode sensing of Cr(VI), TNP, and AA.
• The synthesized N-CDs possess excellent photostability, low toxicity, and biocompatibility.
• N-CDs show significant potential for applications in biosensing and biomedical optical imaging.