Researchers have demonstrated that a glass surface embedded with self-assembled gold nanoparticles can improve resolution using a conventional widefield microscope, allowing for high-resolution fluorescence microscopy capable of high-speed imaging of living cells.
Because optical microscopes magnify light to obtain detailed images of a structure, the size of distinguishable objects has long been limited by diffraction—a property of light that causes it to spread when passing through an opening. Using highly advanced optical systems, researchers have been developing techniques to overcome these limitations. Still, many rely on strong lasers, which can damage or even kill living cells, scanning the sample or processing multiple images, preventing real-time imaging.
By changing the surface under the cells, the researchers improved resolution under a conventional widefield microscope to near the diffraction limit.
Fluorescence microscopy involves labeling cell structures of interest with molecules that absorb energy from incoming light and re-emit it as the light of a different color, which is collected to form the image.
Though cells are typically imaged on plain glass, the researchers coated the glass surface with a self-assembled layer of gold nanoparticles covered by a thin silicon dioxide layer, resulting in a metasurface with unique optical properties.
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