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

Kneipp, Janina; Kneipp, Harald; Wittig, Burghardt; Kneipp, Katrin · Nano Lett · 2007

basic_science · Level V

Where this comes from

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.

Medical subject headings