Elucidating Molecule–Plasmon Interactions in Nanocavities with 2 nm Spatial Resolution and at the Single‐Molecule Level

Abstract

The fundamental understanding of the subtle interactions between molecules and plasmons is of great significance for the development of plasmon-enhanced spectroscopy(PES) techniques with ultrahigh sensitivity.However, this information has been elusive due to the complex mechanisms and difficulty in reliably constructing and precisely controlling interactions in well-defined plasmonic systems. Herein, the interactions in plasmonic nanocavities of filmcoupled metallic nanocubes (NCs) are investigated. Through engineering the spacer layer,m olecule-plasmon interactions were precisely controlled and resolved within 2nm. Efficient energy exchange interactions between the NCs and the surface within the 1-2 nm range are demonstrated. Additionally, optical dressed molecular excited states with ah uge Lamb shift of % 7meV at the single-molecule (SM) level were observed. This work provides ab asis for understanding the underlying molecule-plasmon interaction, paving the wayf or fully manipulating light-matter interactions at the nanoscale.

Amplified Fluorescence by Hollow-Porous Plasmonic Assembly: A New Observation and Its Application in Multiwavelength Simultaneous Detection

“…The fluorophores positioned in this appropriate zone could participate in the most effective coupling interaction to enhance the signal. Generally, there are three types of interaction modes between fluorophores and metal nanofilms: quenching, plasmon coupling, and FS emission. − When the fluorophores are sufficiently close to the surface, the energy of the fluorophores is transferred to the metal surface through a nonradiative manner, and quenching is dominant. ,, In contrast, the far-field radiation of FS dominates when the distance exceeds 500 nm. , The effective coupling range is approximately 20–200 nm, and the signal gradually increases within tens of nanometers . This is consistent with the results obtained from the normal SPCE with various thicknesses of the QD layer (Figure S9b).…”

“…34−36 When the fluorophores are sufficiently close to the surface, the energy of the fluorophores is transferred to the metal surface through a nonradiative manner, and quenching is dominant. 18,37,38 In contrast, the far-field radiation of FS dominates when the distance exceeds 500 nm. 39,40 The effective coupling range is approximately 20−200 nm, 41 and the signal gradually increases within tens of nanometers.…”

Manipulating the light-matter interactions in plasmonic nanocavities at 1 nm spatial resolution

“…It constructs a concrete placement of emitters to manipulate the light at the nanoscale and respond quickly to the changes in the system. Through embedding emitters into the gap of plasmonic nanocavity, such as molecules 28 , quantum dots 29 , or transition metal dichalcogenides (TMDs) 30 – 32 , the desired configuration for manipulating light-matter interactions can be built. However, few studies on the vertical distribution of the actual system coupling in plasmonic nanocavities.…”

Direct Imaging of Weak‐to‐Strong‐Coupling Dynamics in Biological Plasmon–Exciton Systems

“…In weakcoupling regimes, spontaneous emission rate can be enhanced due to the modified photonic density of state (Purcell factor), which has been widely applied in nanophotonic devices and biosensing applications. [6][7][8][9][10] In intermediatecoupling regimes, the scattering or extinction spectrum starts to exhibit the dip (Fano interference), while the fluorescence (FL) intensity reaches its maximum value. [11][12][13] However, for strongcoupling regimes, new hybridized eigenstates occur (Rabi splitting) when the energy exchange exceeds the dissipation rate.…”