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Synthesis, Cellular Delivery and In vivo Application of Dendrimer-based pH Sensors
Published on: September 10, 2013
Development of ultrabright semiconducting polymer dots for ratiometric pH sensing
Yang-Hsiang Chan1, Changfeng Wu, Fangmao Ye
1Department of Chemistry, University of Washington, Seattle, Washington 98195, USA.
Analytical Chemistry
|January 20, 2011
Summary
Researchers developed new polymer nanoparticles (Pdots) for pH sensing. These ultrabright probes enable ratiometric pH measurements in cells, offering a stable and reversible method for biological imaging.
Area of Science:
- Nanotechnology
- Biomedical Engineering
- Materials Science
Background:
- Semiconducting polymer nanoparticles (Pdots) are emerging as sensitive probes for biological applications.
- Förster resonance energy transfer (FRET) enables ratiometric sensing, enhancing measurement accuracy.
- Developing robust nanoprobes for intracellular pH monitoring is crucial for biological research.
Purpose of the Study:
- To develop poly(2,5-di(3',7'-dimethyloctyl)phenylene-1,4-ethynylene) (PPE) Pdots as a platform for FRET-based ratiometric pH nanoprobes.
- To couple the pH-sensitive dye fluorescein to PPE Pdots and evaluate their performance.
- To demonstrate the utility of these nanoprobes for intracellular pH measurement in live cells.
Main Methods:
- Synthesized PPE Pdots as a pH-insensitive semiconducting polymer core.
- Developed and compared three coupling strategies for attaching the pH-sensitive dye fluorescein to PPE Pdots.
- Utilized ratiometric methodology with a single excitation wavelength and two emission peaks for pH sensing.
- Investigated the linear range, reversibility, and stability of the developed nanoprobes.
- Applied the nanoprobes for intracellular pH measurements in HeLa cells via endocytosis.
Main Results:
- Successfully developed fluorescein-coupled PPE Pdots for ratiometric pH sensing.
- Established a linear pH sensing range from pH 5.0 to 8.0, suitable for cellular studies.
- Demonstrated excellent reversibility and stability of the Pdots in pH measurements.
- Successfully measured intracellular pH in HeLa cells, confirming probe utility in biological systems.
Conclusions:
- Fluorescein-coupled PPE Pdots provide a rapid, robust, and stable platform for ratiometric pH nanoprobes.
- The developed nanoprobes are suitable for intracellular pH determination and imaging applications.
- This FRET-based approach offers a valuable tool for studying cellular pH dynamics.
