CdSe-ZnS quantum dots for selective and sensitive detection and quantification of hypochlorite

Area of Science:

• Nanotechnology
• Analytical Chemistry
• Biomedical Engineering

Background:

• Quantum dots (QDs) are fluorescent nanoparticles with tunable optical properties.
• Hypochlorite/hypochlorous acid (HClO) is a key biomarker in various physiological and environmental processes.
• Developing selective and sensitive probes for HClO detection is crucial.

Purpose of the Study:

• To fabricate water-soluble quantum dots (QDs) with diverse organic coatings.
• To evaluate the sensitivity of these QDs for detecting hypochlorite/hypochlorous acid (HClO).
• To assess the potential of optimized QDs as probes in chemical and biological applications.

Main Methods:

• Synthesis of four types of water-soluble QDs with varying organic coating layers.
• Examination of QD fluorescence quenching by HClO.
• Application of QDs for HClO quantification in tap water.
• Monitoring myeloperoxidase activity and fluorescent imaging in HL60 cells.

Main Results:

• QDs with hydrocarbon and carboxylate coatings exhibited the highest sensitivity for HClO detection.
• QDs with carboxylate coating layers (QDs-poly-CO(2)(-)) effectively quantified HClO in tap water.
• QDs-poly-CO(2)(-) demonstrated excellent selectivity for hypochlorite over other reactive oxygen species.
• QDs-poly-CO(2)(-) enabled fluorescent imaging for HClO detection in HL60 cells.

Conclusions:

• QDs with carboxylate coating layers are highly sensitive and selective probes for HClO.
• QDs-poly-CO(2)(-) show significant promise for monitoring HClO in diverse chemical and biological systems.
• This QD-based probe facilitates accurate HClO quantification and real-time imaging applications.