Excitation–Emission Synchronization-Mediated Directional Fluorescence: Insight into Plasmon-Coupled Emission at Vibrational Resolution

Abstract

Light−matter interactions have always been a fundamentally significant topic that has attracted much attention. It is important to reveal a fluorophore−plasmon interaction on the nanoscale. However, as a powerful investigative tool, fluorescence spectroscopy still suffers from a limited spectral resolution and the susceptibility to interfering substances. In this work, excitation−emission synchronization-mediated surface-plasmon-coupled emission (EES-SPCE) is proposed to break the bottleneck. By actively screening the energy transitions for observation, an improved spectral resolution has been achieved, which is advantageous to the investigation of the fluorophore−plasmon interactions under different coupling modes. The spectral information related to the plasmonic interactions through tuning vibrational energy levels is clearly distinguished at directional emission angles. EES-SPCE is demonstrated to selectively and efficiently extract the coupled emission from the vibrational resolution, which would open up the opportunity to improve the capability of spectral feature identification and signal collection for practical applications of plasmonic fluorescence spectroscopy.

Surface Plasmon-Assisted Fluorescence Enhancing and Quenching: From Theory to Application

“…The spectral properties of distance-dependent SPCE are characterized in detail with a varying thickness of polymer matrix overlying a metallic surface. , To extend the spectrum utility in practical measurements, the excitation and emission spectra are recorded synchronously based on a polymer matrix to parse the spectra-dependent SPCE as shown in Figure . Here, the energy transitions for observation are screened actively on a 25 nm poly­(methyl methacrylate) (PMMA) layer under different coupling modes, and the spectral information related to the silver-plasmonic interactions is first interpreted in detail through tuning vibrational energy levels.…”

“…(b) Typical plasmonic fluorescence spectrum (red curve) and the corresponding EES-SPCE spectra (violet and green curves). Reproduced from ref . Copyright [2020] American Chemical Society.…”

“…112,113 To extend the spectrum utility in practical measurements, the excitation and emission spectra are recorded synchronously based on a polymer matrix to parse the spectra-dependent SPCE as shown in Figure 12. 114 Here, the energy transitions for observation are screened actively on a 25 nm poly(methyl methacrylate) (PMMA) layer under different coupling modes, and the spectral information related to the silver-plasmonic interactions is first interpreted in detail through tuning vibrational energy levels. The coupled emission from a vibrational resolution is selectively and efficiently extracted for improving the capability of a spectral feature identification and the signal collection for practical applications.…”

Derivative Matrix-Isopotential Synchronous Spectrofluorimetry and Hantzsch Reaction: A Direct Route to Simultaneous Determination of Urinary δ-Aminolevulinic Acid and Porphobilinogen

“…Despite the extensive use, the considerable background fluorescence and the spectral overlap contributed by the interfering components are liable to pose a formidable diagnostic challenge for conventional fluorescence spectrometry in case of complex multi-component analysis. The technological advancement of synchronous fluorescence spectrometry (SFS) in biological applications shows great promise in solving this problem by taking advantage of spectral simplification, band narrowing, and minimized scattering interference ( Lecrenier et al, 2018 ; Elmas et al, 2019 ; Kumar, 2019 ; Ouyang et al, 2019 ; Zhao et al, 2020 ). SFS exploits simultaneous scanning for excitation and emission wavelengths.…”

Plasmon Coupling Enhanced Micro‐Spectroscopy and Imaging for Sensitive Discrimination of Membrane Domains of a Single Cell

“…[24][25][26][27] Surface plasmons (SPs) are located on the surface of a metal film and can be effectively excited by incident light at the surface plasmon resonance (SPR) angle. [28][29] The near-field enhanced technique SPCE involves the coupling of excited molecules and SPs [28][29][30][31][32][33] and is capable of selectively mediating the fluorescence emission at the basal membrane that originates from the region of tens of nanometres from the metal surface. [34][35][36] Researchers, including our group, have utilized SPCE to study basal cellular membrane-related activities.…”