Bouquiaux Charlotte, Tonnelé Claire, Castet Frédéric, Champagne Benoît
Theoretical Chemistry Laboratory, Unit of Theoretical and Structural Physical Chemistry, Namur Institute of Structured Matter, University of Namur, Rue de Bruxelles, 61, B-5000 Namur, Belgium.
University of Bordeaux, Institut des Sciences Moléculaires, UMR 5255 CNRS, Cours de la Libération 351, F-33405 Talence Cedex, France.
J Phys Chem B. 2020 Mar 19;124(11):2101-2109. doi: 10.1021/acs.jpcb.9b10988. Epub 2020 Mar 10.
The second harmonic signal of an amphiphilic dye embedded in a lipid bilayer has been calculated by combining molecular dynamics simulations and quantum chemistry calculations based on density functional theory. This computational approach provides insight into the morphology and dynamics of the fully hydrated biological system and the relationships linking the geometry and the environment of the dye to the amplitude of its second-order nonlinear optical response. The results point out a significant enhancement of the dynamic first hyperpolarizability of the dye induced by its interaction with the membrane and highlight the relative importance of dynamical, steric, and electrostatic effects. This computational scheme is thus particularly relevant for rationalizing the nonlinear optical contrasts revealed by second harmonic imaging microscopy of exogenous dyes embedded in biological media.
通过结合基于密度泛函理论的分子动力学模拟和量子化学计算，已计算出嵌入脂质双层中的两亲性染料的二次谐波信号。这种计算方法有助于深入了解完全水合的生物系统的形态和动力学，以及将染料的几何结构和环境与其二阶非线性光学响应幅度联系起来的关系。结果表明，染料与膜的相互作用会显著增强其动态第一超极化率，并突出了动力学、空间位阻和静电效应的相对重要性。因此，这种计算方案对于解释生物介质中嵌入的外源性染料的二次谐波成像显微镜所揭示的非线性光学对比度特别有意义。
