Objective-Induced Point Spread Function Aberrations and Their Impact on Super-Resolution Microscopy.

This study demonstrates how different microscope objectives can lead to asymmetric imaging aberrations in the point spread function of dipolar emitters, which can adversely affect the quality of fit in super-resolution imaging. Luminescence from gold nanorods was imaged with four different objectives to measure the diffraction-limited emission and characterize deviations from the expected dipolar emission patterns. Each luminescence image was fit to a three-dipole emission model to generate fit residuals that visually relay aberrations in the point spread function caused by the different microscope objectives.

Triplet-state-mediated super-resolution imaging of fluorophore-labeled gold nanorods.

Triplet-state-mediated super-resolution imaging was used to map the positions of fluorescently labeled double-stranded DNA bound to the surface of gold nanorods. In order to isolate individual fluorophores bound to the nanorod surface, imaging conditions were optimized such that the majority of the fluorophores were forced into a triplet dark state, and fluorescence from approximately one molecule at a time was detected. The fluorescence from the emitting single molecule was then fit to a two-dimensional (2D) Gaussian to localize its position relative to the nanorod substrate.

Ground state depletion microscopy for imaging interactions between gold nanowires and fluorophore-labeled ligands.

Ground state depletion with individual molecule return (GSDIM) is used to interrogate the location of individual fluorescence bursts from fluorophore-labelled DNA molecules on gold nanowire surfaces. Carboxytetramethyl rhodamine (TAMRA)-labelled double-stranded DNA molecules were bound to the surface of gold nanowires via gold-thiol linkages. Individual fluorescence bursts were spatially localized using point spread function fitting and used to reconstruct the image of the underlying nanowire.