Tiny nanoparticles have huge potential inside our bodies. These hexagonal specks of magnesium, each 50,000 smaller than a beach ball, could be injected into our tissues then zapped by lasers – the light particles (photons) collide with electrons buzzing around the surface of the metal, generating a haze of rippling waves called plasmons around each particle. Plasmonic waves are sensitive to changes in their surroundings, so may be used to snoop on chemical reactions happening nearby, such as a patient’s metabolism. Here computer model simulations (top row), and experiments (bottom) show how different wavelengths of light create different electric field patterns around the particles. Though usually completely harmless, with a different setup, plasmonic waves could be targeted to fry cancer cells. These magnesium nanoparticles are cheaper than those made from gold or silver, and their unique shape is allowing nanoengineers to dream up useful new structures.
Written by John Ankers
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