A Comparative Study of Synthesis Routes for Nitrogen-Doped Graphene Quantum Dots in Fluorescence Quenching-Based...

Area of Science:

• Materials Science
• Environmental Science
• Analytical Chemistry

Background:

• Nitrite detection in water is vital for environmental and public health.
• Traditional nitrite detection methods are often complex and require laboratory settings.
• Development of cost-effective, portable sensors is needed for on-site monitoring.

Purpose of the Study:

• To comparatively study synthesis routes for nitrogen-doped graphene quantum dots (N-GQDs).
• To develop a low-cost, fluorescence quenching-based sensor for nitrite detection.
• To establish a foundation for portable, on-site water quality monitoring devices.

Main Methods:

• Comparative analysis of different synthesis routes for N-GQDs.
• Facile, one-pot hydrothermal synthesis using citric acid and ethylenediamine.
• Fabrication of a custom-built, low-cost optoelectronic setup for sensor application.

Main Results:

• Optimized N-GQDs synthesized via hydrothermal method showed superior optical properties and uniform size (3.01 ± 0.41 nm).
• The sensor demonstrated a robust linear response for nitrite detection in the range of 0-50 μM.
• A limit of detection (LOD) of 7.37 μM was achieved for nitrite.

Conclusions:

• The synthesis route significantly impacts N-GQDs' performance for nitrite sensing.
• The developed N-GQD sensor is effective for sensitive and low-cost nitrite detection.
• This research supports the development of portable devices for real-time water quality monitoring.