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Dynamic pH measurements of intracellular pathways using nano-plasmonic assemblies
Kazuki Bando1, Zhiqiang Zhang, Duncan Graham
1Department of Applied Physics, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan. fujita@ap.eng.osaka-u.ac.jp.
The Analyst
|July 15, 2020
Summary
Researchers visualized intracellular pH changes using plasmonic silver nano-assemblies and surface-enhanced Raman scattering (SERS). This method tracks pH dynamics during cellular transport, offering new insights into biological processes.
Area of Science:
- Nanotechnology
- Biophysics
- Analytical Chemistry
Background:
- Intracellular pH dynamics are crucial for cellular functions.
- Visualizing real-time pH changes within living cells remains challenging.
- Surface-enhanced Raman scattering (SERS) offers high sensitivity for molecular detection.
Purpose of the Study:
- To develop a novel method for spatiotemporal visualization of intracellular pH changes.
- To utilize plasmonic silver nano-assemblies for in vivo pH monitoring.
- To investigate pH variations during intracellular transport processes.
Main Methods:
- Functionalization of silver (Ag) nano-assemblies with 4-mercaptobenzoic acid (p-MBA) for pH sensing.
- Simultaneous 3D nanoparticle tracking and SERS measurements within living cells.
- Analysis of SERS spectra to estimate local pH along nanoparticle pathways.
Main Results:
- Demonstrated visualization of intracellular pH dynamics with high spatial (tens of nanometers) and temporal (200 ms) resolution.
- Successfully traced pH trajectories of nano-assemblies during intracellular transport.
- Observed pH changes associated with organelle interactions like endosomal trafficking and lysosomal fusion.
Conclusions:
- Plasmonic Ag nano-assemblies enable unprecedented spatiotemporal mapping of intracellular pH.
- This SERS-based approach establishes a new paradigm for dynamic intracellular analysis.
- The technique provides new capabilities for rapid biological analysis using SERS.
