Spectral Reshaping of Single Dye Molecules Coupled to Single Plasmonic Nanoparticles.
Stephen A LeeJulie Suzanne BiteenPublished in: The journal of physical chemistry letters (2019)
Fluorescent molecules are highly susceptible to their local environment. Thus, a fluorescent molecule near a plasmonic nanoparticle can experience changes in local electric field and local density of states that reshape its intrinsic emission spectrum. By avoiding ensemble averaging while simultaneously measuring the super-resolved position of the fluorophore and its emission spectrum, single-molecule hyperspectral imaging is uniquely suited to differentiate changes in the spectrum from heterogeneous ensemble effects. Thus, we uncover for the first time single-molecule fluorescence emission spectrum reshaping upon near-field coupling to individual gold nanoparticles using hyperspectral super-resolution fluorescence imaging, and we resolve this spectral reshaping as a function of the nanoparticle/dye spectral overlap and separation distance. We find that dyes bluer than the plasmon resonance maximum are red-shifted and redder dyes are blue-shifted. The primary vibronic peak transition probabilities shift to favor secondary vibronic peaks, leading to effective emission maxima shifts in excess of 50 nm, and we understand these light-matter interactions by combining super-resolution hyperspectral imaging and full-field electromagnetic simulations.
Keyphrases
- single molecule
- living cells
- fluorescence imaging
- gold nanoparticles
- optical coherence tomography
- atomic force microscopy
- photodynamic therapy
- high resolution
- energy transfer
- aqueous solution
- solid state
- label free
- convolutional neural network
- fluorescent probe
- highly efficient
- high frequency
- dual energy
- neural network
- mass spectrometry
- iron oxide
- magnetic resonance
- liquid chromatography