Ratiometric Fluorescent Sensor for Hg²⁺ and Thiophanate-Methyl Based on Nitrogen-Doped Carbon Dots and Rhodamine B

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Materials Science

Background:

• Mercury (Hg²⁺) and thiophanate-methyl (TM) are prevalent environmental and food contaminants.
• Accurate detection methods are crucial for monitoring these pollutants.

Purpose of the Study:

• To develop a novel ratiometric fluorescent sensor for simultaneous detection of Hg²⁺ and TM.
• To utilize nitrogen-doped carbon dots (N-CDs) and Rhodamine B (RhB) for dual-analyte sensing.

Main Methods:

• Fabrication of a ratiometric fluorescent sensor based on N-CDs and RhB.
• Utilizing fluorescence quenching and recovery mechanisms for Hg²⁺ and TM detection.
• Optimizing sensor conditions and validating performance with real-world samples.

Main Results:

• The sensor demonstrated linear detection ranges for Hg²⁺ (0.50-50 μM) and TM (0.50-3.0 mg/L).
• Achieved low detection limits of 0.15 μM for Hg²⁺ and 0.017 mg/L for TM.
• Exhibited excellent selectivity, with minimal interference from other ions and pesticides.

Conclusions:

• A novel dual-functional ratiometric sensor for cascade detection of Hg²⁺ and TM was successfully developed.
• The sensor shows significant potential for practical applications in monitoring environmental and food samples.