Broadband Plasmonic Nanoantennas for Multi‐Color Nanoscale Dynamics in Living Cells

Abstract

At the plasma membrane level, extensive research has demonstrated that multiple molecules, such as proteins and lipids, interact in a dynamic fashion creating transient nanoscale compartments of functional activity. [6][7][8][9][10] Such findings were revealed owing to the recent development of different optical techniques aimed at improving both spatial and temporal resolution beyond that of conventional diffraction-limited optical methods. [10][11][12][13][14][15] Yet, monitoring dynamic multi-molecular interactions in living cells at the nanoscale remains challenging.With the advancement of single-molecule and super-resolution approaches, multiple techniques have been implemented aiming to reduce the illumination volume set by diffraction, thus enabling single-molecule dynamic studies at high labeling conditions in living cells on the nanoscale. For instance, stimulated emission depletion microscopy (STED) [10] and metallic nanoapertures [16][17][18] reduce the illumination area down to 50-200 nm in diameter. However, in the case of STED, both the high laser powers required and the increased photobleaching constitute significant drawbacks for its routine application in living cells. [19] Fluorescence cross-correlation spectroscopy moreover, although dual-color STED is nowadays widely used for superresolution imaging in fixed cells, [20] its extension to living cells

Heterogeneous anomalous transport in cellular and molecular biology

“…Various mechanisms underlying anomalous diffusion in plasma membranes have been reviewed [239,240]. For example, anomalous subdiffusion can be caused by transient immobilisation and spatial heterogeneity [19] or specific interactions between molecules which temporarily modify their diffusive behaviour [241][242][243][244].…”

Time-Domain Topology Optimization of Arbitrary Dispersive Materials for Broadband 3D Nanophotonics Inverse Design

“…The method is tested, as an example, on the optimization of dispersive nanostructures for field localization. Optical nanocavities that confine and store light over a broad bandwidth are of great importance to several areas of optics, such as in quantum information for single photon emission, , spectroscopy, , coherent plasmon generation, enhancing the interaction between photons and electrons in semiconductor devices (e.g., for lasers), applications in nonlinear optics, or energy harvesting (e.g., in photovoltaics) . To date, most nanostructures for field enhancement are invariant in one direction.…”