Quantum dot FRET-based probes in thin films grown in microfluidic channels

Area of Science:

• Biotechnology
• Materials Science
• Analytical Chemistry

Background:

• Fluorescence resonance energy transfer (FRET) probes are valuable tools for detecting biological activity.
• Quantum dots offer unique optical properties but their application in bioassays is limited by toxicity concerns.
• Developing novel FRET-based probes is crucial for advancing sensitive and safe bioanalytical methods.

Purpose of the Study:

• To develop novel fluorescence resonance energy transfer (FRET)-based quantum dot probes for detecting proteolytic activity.
• To incorporate cadmium selenide/zinc sulfide (CdSe/ZnS) quantum dots into a polymeric film for enhanced probe stability and functionality.
• To demonstrate the utility of these probes for real-time monitoring of enzyme activity and address quantum dot toxicity.

Main Methods:

• Layer-by-layer deposition of polyelectrolytes to create a film incorporating CdSe/ZnS quantum dots (donors) and rhodamine acceptors.
• Utilizing FRET between quantum dots and rhodamine molecules, with emission color dependent on acceptor proximity.
• Enzymatic cleavage of the film surface to alter FRET efficiency and induce a color change.

Main Results:

• The developed polymeric film exhibited orange emission due to FRET between quantum dots and rhodamine acceptors.
• Enzymatic cleavage resulted in a shift to green emission, indicating successful probe activation.
• The probes enabled real-time monitoring of trypsin activity with high sensitivity.
• Application in microfluidic channels allowed for bioanalysis of small sample volumes and single-cell studies.

Conclusions:

• The novel quantum dot FRET-based probes are effective for detecting proteolytic activity.
• This probe design alleviates toxicity concerns associated with quantum dots in bioassays.
• The probes demonstrate significant potential for advanced bioanalytical applications, including microfluidics and single-cell analysis.