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

Janina Kneipp; Harald Kneipp; Burghardt Wittig; Katrin Kneipp

doi:10.1021/nl071418z

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.

Authors

Janina Kneipp¹, Harald Kneipp, Burghardt Wittig, Katrin Kneipp

Affiliation

¹ Harvard University Medical School, Wellman Center for Photomedicine, Boston, Massachusetts 02114, USA. jkneipp@janina-kneipp.de

PMID: 17696561
DOI: 10.1021/nl071418z

Abstract

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