Nontoxic Material Used to Upconvert Low-energy Photons

Researchers at the University of California, Riverside (UC Riverside) and the University of Texas at Austin demonstrated the use of nontoxic silicon nanocrystals to convert low-energy photons into high-energy ones. The use of nontoxic materials for photon upconversion could help advance the development of photodynamic treatments for cancer. Ultraviolet (UV) light can form free radicals that can attack cancer tissue. However, it does not travel deep enough into tissues to generate therapeutic radicals close to the cancer site. Near-infrared (NIR) light, in contrast, can penetrate deep into tissues, but is not high-energy enough to generate free radicals. While photon up-conversion can provide the advantages of both UV and NIR light,...