Correlative light-electron microscopy using FWM of single gold nanoparticles. (IMAGE)
Caption
a) Sketch of FWM set-up. Short optical pulses in resonance with the optical absorption peak of a gold nanoparticle (AuNP) are focused onto the sample, using an inverted microscope, and generate a FWM field which is collected in epi-geometry, detected with a heterodyne interference scheme. AOM: acousto-optic modulator. (P)BS: (polarising) beam splitter. P: polariser. MO: microscope objective. b) Example of volumetric FWM microscopy on a single 10nm-radius AuNP, with line-profiles along x and z at the y-position in the centre of the AuNP and corresponding Gaussian fits (red lines). The nanoscale centroid localisation precision in 3D (δx0=1.1nm, δz0=4.3nm) and the fullwidth at half maximum (FWHM) obtained from the fit are indicated. c) CLEM of 10nm-radius AuNPs bound to the epidermal growth factor protein in human cancer (HeLa) cells. Individual AuNPs are detected background-free in FWM (left), measured directly on 300nm thick resin sections post-cell fixation, ready for EM analysis. The same pattern is found in transmission EM (TEM), highlighted by the orange circles. Two cells are visible, with their nucleus indicated (N). The nucleus is surrounded by the organelle-containing cytoplasm. The top row shows crops (0.2µm×0.2µm) of the TEM image for each AuNP as numbered. The confocal reflection image simultaneously acquired with FWM is shown underneath the TEM image. Grey scales are from 0 to M as indicated (M=1 correspond to 31mV rms detected).
Credit
by Iestyn Pope, Hugh Tanner, Francesco Masia, Lukas Payne, Kenton Paul Arkill, Judith Mantell, Wolfgang Langbein, Paola Borri and Paul Verkade
Usage Restrictions
Credit must be given to the creator.
License
CC BY