Metamaterial-Assisted Illumination Nanoscopy with Exceptional Axial Resolution

Recent advancements in optical metamaterials have opened new possibilities in the exciting field of super-resolution microscopies. The far-field metamaterial-assisted illumination nanoscopies (MAINs) have, very recently, enhanced the lateral resolution to one-fifteenth of the optical wavelength. However, the axial localization accuracy of fluorophores in the MAINs remains rarely explored. Here, a MAIN with a nanometer-scale axial localization accuracy is demonstrated by monitoring the distance-dependent photobleaching dynamics of the fluorophores on top of an organic hyperbolic metamaterial (OHM) substrate under a wide-field single-objective microscope. With such a regular experimental configuration, 3D imaging of various biological samples with the resolution of approximate to 40 nm in the lateral dimensions and approximate to 5 nm in the axial dimension is realized. The demonstrated imaging modality enables the resolution of the 3D morphology of nanoscopic cellular structures with a significantly simplified experimental setup. It demonstrates that with an organic hyperbolic metamaterial substrate, both the lateral and axial imaging resolutions of a fluorophore can be improved by exploiting the metamaterial's hyperbolic dispersion and the resultant photobleaching-dynamics variation of the fluorophore. The demonstrated far-field metamaterial-assisted illumination nanoscopy with a spatial resolution of approximate to 40 nm in the lateral dimensions and approximate to 5 nm in the axial dimension offers many exciting possibilities in biological research. image