Highly sensitive glutathione assay and intracellular imaging with functionalized semiconductor quantum dots

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Analytical Chemistry

Background:

• Glutathione (GSH) is crucial in biological systems and linked to human diseases.
• Developing fluorescent probes for GSH sensing and bioimaging using semiconductor quantum dots (QDs) is an emerging area.
• Existing methods for GSH detection may have limitations in sensitivity, selectivity, or real-time imaging.

Purpose of the Study:

• To engineer a stable and biocompatible fluorescent nanoprobe for selective and sensitive detection of GSH.
• To investigate the use of manganese dioxide (MnO2) nanosheets on silica-coated quantum dots (QD@SiO2) for GSH sensing.
• To demonstrate the application of the developed nanoprobe for real-time intracellular GSH imaging.

Main Methods:

• In situ growth of manganese dioxide nanosheets (MnO2) on silica-coated semiconductor quantum dots (QD@SiO2).
• Utilizing the fluorescence quenching and recovery mechanism of QD@SiO2-MnO2 in response to GSH.
• Testing selectivity against potential interfering substances and evaluating biocompatibility and cellular uptake.

Main Results:

• The QD@SiO2-MnO2 nanoprobe exhibited quenched fluorescence, which was efficiently recovered upon addition of GSH due to MnO2 decomposition.
• The nanosensor demonstrated a rapid response, a low detection limit, and high selectivity for GSH.
• The engineered QDs showed good biocompatibility and cellular uptake, enabling successful real-time imaging of intracellular GSH.

Conclusions:

• The developed MnO2-engineered QD nanoprobe is a promising tool for selective and sensitive GSH detection.
• This approach facilitates real-time imaging of intracellular GSH dynamics.
• Semiconductor QD-based probes hold potential for advancing the study of GSH-related pathophysiological events.