One- and two-photon excited optical ph probing for cells using surface-enhanced Raman and hyper-Raman nanosensors

Nano Lett. 2007 Sep;7(9):2819-23. doi: 10.1021/nl071418z. Epub 2007 Aug 16.


We demonstrate spatially resolved probing and imaging of pH in live cells by mobile and biocompatible nanosensors using surface-enhanced Raman scattering (SERS) of 4-mercaptobenzoic acid (pMBA) on gold nanoaggregates. Moreover, we also show that this concept of pH nanosensors can be extended to two-photon excitation by using surface-enhanced hyper-Raman scattering (SEHRS). In addition to the advantages of two-photon excitation, the SEHRS sensor enables measurements over a wide pH range without the use of multiple probes.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Biosensing Techniques / instrumentation*
  • Biosensing Techniques / methods
  • Equipment Design
  • Equipment Failure Analysis
  • Hydrogen-Ion Concentration*
  • Mice
  • Microscopy, Fluorescence, Multiphoton / instrumentation*
  • Microscopy, Fluorescence, Multiphoton / methods
  • NIH 3T3 Cells
  • Nanotechnology / instrumentation*
  • Nanotechnology / methods
  • Spectrum Analysis, Raman / instrumentation*
  • Spectrum Analysis, Raman / methods