Related Experiment Video
Updated: Jul 13, 2026
Biomolecular Imaging of Cellular Uptake of Nanoparticles using Multimodal Nonlinear Optical Microscopy
Published on: May 16, 2022
One- and two-photon excited optical ph probing for cells using surface-enhanced Raman and hyper-Raman nanosensors
Janina Kneipp1, Harald Kneipp, Burghardt Wittig
1Harvard University Medical School, Wellman Center for Photomedicine, Boston, Massachusetts 02114, USA. jkneipp@janina-kneipp.de
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.
