Electro-optic response of second-harmonic generation membrane potential sensors.
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.
Moreaux
L
L
Neurophysiologie et Nouvelles Microscopies, Ecole Superieure de Physique et de Chimie Industrielles, Institut National de la Santé et de la Recherche Scientifique, EPI 00-02, Paris, France.
Pons
T
T
Dambrin
V
V
Blanchard-Desce
M
M
Mertz
J
J
D002468:Cell Physiological Phenomena; D004594:Electrophysiology / Q000379:methods*; D008564:Membrane Potentials; D008853:Microscopy / Q000379:methods*; D008962:Models, Theoretical; D055095:Optics and Photonics