Onion-like Layers Help New Nanoparticle Glow
A new, onion-like nanoparticle could open new frontiers in biomaging, solar energy harvesting and light-based security techniques. The research was led by the Institute for Lasers, Photonics, and Biophotonics at the State University of New York University at Buffalo and the Harbin Institute of Technology in China, with contributions from the Royal Institute of Technology in Sweden, Tomsk State University in Russia, and the University of Massachusetts Medical School. The particle’s innovation lies in its layers: a coating of organic dye, a neodymium-containing shell, and a core that incorporates ytterbium and thulium. Together, these strata convert invisible near-infrared light to higher energy blue and UV light with record-high efficiency, a trick that could improve the performance of technologies ranging from deep-tissue imaging and light-induced therapy to security inks used for printing money. When it comes to bioimaging, near-infrared light could be used to activate the light-emitting nanoparticles deep inside the body, providing high-contrast images of areas of interest. In the realm of security, nanoparticle-infused inks could be incorporated into currency designs; such ink would be invisible to the naked eye, but glow blue when hit by a low-energy laser pulse — a trait very difficult for counterfeiters to reproduce.