Eco-Friendly Cdots-Based Dual-Mode Energy/Electron Transfer Pathways for High-Efficiency p-Nitrophenol Monitoring

Area of Science:

• Environmental Science
• Analytical Chemistry
• Materials Science

Background:

• p-nitrophenol (p-Nit) is a common environmental pollutant requiring efficient detection methods for ecological protection.
• Carbon nanodots (Cdots) are emerging nanomaterials with tunable optical properties for sensing applications.

Purpose of the Study:

• To develop a sensitive and selective fluorescent sensor for p-nitrophenol (p-Nit) detection.
• To utilize surface-aminated carbon nanodots (A-Cdots) for specific recognition and quantification of p-Nit.

Main Methods:

• Synthesis of surface-aminated carbon nanodots (A-Cdots) via controlled precursor selection and reaction design.
• Fluorescent sensing mechanism involving hydrogen bonding and dual-mode electron/energy transfer (inner filter effect).
• Characterization of A-Cdots and evaluation of sensing performance, including limit of detection and selectivity.

Main Results:

• A-Cdots demonstrated specific recognition of p-Nit through hydrogen bonding interactions.
• The fluorescence intensity of A-Cdots was modulated by p-Nit via dual-mode electron/energy transfer, enabling fluorescent sensing.
• Achieved a high quenching constant (Ksv) of 1.0 × 10^5 M^-1 and a low limit of detection (LOD) of 47 nM for p-Nit.
• The sensor exhibited rapid and selective quantification of p-Nit in real sewage samples without complex pretreatment.

Conclusions:

• Surface-aminated carbon nanodots (A-Cdots) provide a highly selective and sensitive platform for p-nitrophenol (p-Nit) detection.
• The developed fluorescent sensor is suitable for rapid, on-site analysis of p-Nit in environmental samples like sewage.
• This work highlights the potential of functionalized carbon nanodots in environmental monitoring and pollutant analysis.