Medves Marco, Toffoli Daniele, Stener Mauro, Sementa Luca, Fortunelli Alessandro
Dipartimento di Scienze Chimiche e Farmaceutiche, Università di Trieste, Via L. Giorgieri 1, 34127 Trieste, Italy.
CNR-ICCOM & IPCF, Consiglio Nazionale delle Ricerche, via G. Moruzzi 1, Pisa, 56124, Italy.
J Phys Chem A. 2022 Sep 8;126(35):5890-5899. doi: 10.1021/acs.jpca.2c04168. Epub 2022 Aug 24.
A time-dependent density functional theory (TDDFT) computational approach is employed to study the optical coupling between a plasmonic system (a Ag nanorod) and a fluorescent dye (BODIPY). It is found that the BODIPY dye can interact with a plasmonic system in a rather different and selective way according to the mutual orientation of the fragments. Indeed, (i) the plasmon excitation turns out to be sensitive to the presence of the BODIPY transition and (ii) this can lead to amplify or suppress the resonance accordingly to the relative orientation of the corresponding transition dipoles. To understand the coupling mechanism, we analyze the shape of the induced density in real space and the Individual Component Map of the Oscillator Strength (ICM-OS) plots and achieve a simple rationalization and insight on the origin and features of the coupling. The resulting possibility of understanding plasmon/fluorophore interactions by simple qualitative arguments opens the way to a rational design of hybrid (plasmon + dye) systems with the desired optical behavior.
采用含时密度泛函理论（TDDFT）计算方法研究了等离子体系统（银纳米棒）与荧光染料（BODIPY）之间的光耦合。研究发现，根据片段的相互取向，BODIPY染料可以以一种截然不同且具有选择性的方式与等离子体系统相互作用。实际上，（i）等离子体激元激发对BODIPY跃迁的存在敏感，并且（ii）这会根据相应跃迁偶极子的相对取向导致共振增强或抑制。为了理解耦合机制，我们分析了实空间中感应密度的形状以及振子强度的个体分量图（ICM - OS），并对耦合的起源和特征实现了简单的合理化解释和洞察。通过简单的定性论证来理解等离子体激元/荧光团相互作用的可能性，为合理设计具有所需光学行为的混合（等离子体激元 + 染料）系统开辟了道路。
