Water-soluble MoS₂ quantum dots are a viable fluorescent probe for hypochlorite

Area of Science:

• Analytical Chemistry
• Materials Science
• Nanotechnology

Background:

• Accurate determination of hypochlorite is crucial for water quality monitoring and disinfectant efficacy assessment.
• Existing methods for hypochlorite detection may have limitations in sensitivity, selectivity, or sample applicability.
• Development of novel fluorescent probes offers potential for enhanced detection capabilities.

Purpose of the Study:

• To develop a novel fluorometric method for the sensitive and selective determination of hypochlorite.
• To synthesize and characterize molybdenum disulfide quantum dots (MoS₂ QDs) for use as fluorescent probes.
• To validate the applicability of the developed method for real-world sample analysis.

Main Methods:

• Synthesis of MoS₂ QDs via a hydrothermal reaction of sodium molybdate with glutathione.
• Characterization of MoS₂ QDs for size, stability, and photoluminescence properties.
• Fluorometric detection of hypochlorite based on the static quenching of MoS₂ QD fluorescence.

Main Results:

• MoS₂ QDs exhibited blue photoluminescence with excitation/emission peaks at 315/412 nm and a quantum yield of 3.7%.
• The fluorescence of MoS₂ QDs was linearly quenched by hypochlorite in a static quenching mechanism.
• The method achieved a detection limit of 0.5 μM for hypochlorite in the concentration range of 5–500 μM.
• Successful application in determining hypochlorite in spiked tap water, lake water, and commercial disinfectants.

Conclusions:

• Molybdenum disulfide quantum dots serve as effective fluorescent probes for hypochlorite detection.
• The developed fluorometric method is sensitive, selective, and suitable for practical applications.
• This approach provides a valuable tool for hypochlorite analysis in environmental and commercial samples.