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Highly photostable wide-dynamic-range pH sensitive semiconducting polymer dots enabled by dendronizing the near-IR
1Department of Chemistry , University of Washington , Seattle , Washington 98195 , USA .
Chemical Science
|October 31, 2017
Summary
Researchers developed new semiconducting polymer dots (Pdots) with enhanced near-infrared emission for improved pH sensing. These brighter, more photostable Pdots overcome limitations of previous sensors, enabling accurate biological pH monitoring.
Area of Science:
- Materials Science
- Nanotechnology
- Biomedical Engineering
Background:
- Semiconducting polymer dots (Pdots) with near-infrared emission have limited pH sensing due to low emitter ratios and poor photostability.
- Existing Pdot-based pH sensors struggle with effective emitter concentration and long-term stability.
Purpose of the Study:
- To develop advanced Pdots that overcome the limitations of low emitter ratio and poor photostability in pH sensing.
- To create a ratiometric pH sensor with enhanced sensitivity, brightness, and photostability using dendronized squaraine emitters within a polyfluorene backbone.
Main Methods:
- Synthesized Pdots by covalently incorporating dendronized squaraine-based pH-responsive near-infrared emitters into a polyfluorene (PFO) backbone.
- Controlled energy transfer from PFO donors to emitters to suppress fluorescence self-quenching and enhance performance.
- Evaluated Pdot performance for pH sensing across the biological pH range.
Main Results:
- Achieved a high emitter concentration (5 mole percent) while suppressing fluorescence self-quenching.
- Developed a ratiometric pH sensor with significantly improved pH sensitivity, brightness, and photostability.
- Demonstrated fast and reversible pH response across the biological pH range (4.7–8.5).
Conclusions:
- The novel Pdots offer a promising solution for highly sensitive and photostable pH sensing.
- Successfully demonstrated intracellular pH mapping using these ultra-bright and photostable Pdots.
- These Pdots represent a significant advancement for biological pH monitoring applications.
