Efficient Mercury Ion Detection in Water: CdTe/CdS/ZnS Quantum Dots as a Simple, Sensitive, and Rapid Fluorescence...

Area of Science:

• Materials Science
• Environmental Science
• Analytical Chemistry

Background:

• Mercury (Hg) poses significant environmental and health risks, demanding accurate detection methods.
• Quantum dots (QDs) offer unique optical properties suitable for sensing applications.
• Developing efficient and selective Hg sensors is crucial for environmental monitoring.

Purpose of the Study:

• To synthesize thioglycolic acid (TGA)-stabilized Cadmium Telluride/Cadmium Sulfide/Zinc Sulfide (CdTe/CdS/ZnS) core/multi-shell quantum dots (QDs).
• To develop a sensitive and selective fluorescent sensor for detecting mercury (Hg²⁺) ions.
• To evaluate the sensor's performance in real-world water samples for environmental monitoring.

Main Methods:

• Photochemical synthesis of CdTe/CdS/ZnS core/multi-shell QDs.
• Characterization using fluorescence spectroscopy, TEM, EDS, FESEM, and XRD.
• Fabrication and testing of a fluorescent sensor for Hg²⁺ detection.

Main Results:

• Successful synthesis and characterization of spherical CdTe/CdS/ZnS QDs.
• The QDs exhibited green fluorescence with significant quenching in the presence of Hg²⁺.
• The sensor achieved a low detection limit (16.32 nM) and selectivity for Hg²⁺ in various water matrices.

Conclusions:

• CdTe/CdS/ZnS QDs are effective for developing a sensitive fluorescent Hg²⁺ sensor.
• The sensor demonstrates reliable performance in environmental water samples.
• Immobilized QDs offer a versatile platform for on-site environmental monitoring.