학술논문
All-Optical Sensing of the Components of the Internal Local Electric Field in Proteins
Document Type
Periodical
Author
Source
IEEE Photonics Journal IEEE Photonics J. Photonics Journal, IEEE. 4(5):1996-2001 Oct, 2012
Subject
Language
ISSN
1943-0655
1943-0647
1943-0647
Abstract
Here, we present a new all-optical method of interrogation of the internal electric field vector inside proteins. The method is based on experimental evaluation of the permanent dipole moment change upon excitation and the pure electronic transition frequency of a fluorophore embedded in a protein matrix. The permanent dipole moment change can be obtained from two-photon absorption measurements. In addition, permanent dipole moment change, tensor of polarizability change, and transition frequency for the free chromophore should be calculated quantum–mechanically. This allows obtaining the components of the electric field by considering the second-order Stark shift. We use the fluorescent protein mCherry as an example to demonstrate the applicability of the method.