Electro-optic response of second-harmonic generation membrane potential sensors

Opt Lett. 2003 Apr 15;28(8):625-7. doi: 10.1364/ol.28.000625.


We quantify and ascertain the nature of the second-harmonic generation (SHG) response of amphiphilic push-pull chromophores to a transmembrane electric field. Our technique is based on the application of an alternating field across labeled giant unilamelar vesicles. For chromophore responses that are purely electro-optic, our technique provides an estimate of photoinduced charge shifts based on the observed dispersion of the field response, in accord with a two-level perturbation theory. These results are applicable to the optimization of membrane potential sensors for SHG microscopy.

MeSH terms

  • Cell Physiological Phenomena
  • Electrophysiology / methods*
  • Membrane Potentials
  • Microscopy / methods*
  • Models, Theoretical
  • Optics and Photonics*