Bright lights, small crystals: Scientists use nanoparticles to capture images of single molecules
When imaging at the single-molecule level, small irregularities known as heterogeneities become apparent – features that are lost in higher-scale, so-called ensemble imaging. At the same time, it has until recently been challenging to develop luminescent probes with the photostability, brightness and continuous emission necessary for single-molecule microscopy. Now, however, scientists in the Molecular Foundry at Lawrence Berkeley National Lab, Berkeley, CA have developed upconverting nanoparticles (UCNPs) under 10 nm in diameter whose brightness under single-particle imaging exceeds that of existing materials by over an order of magnitude. The researchers state that their findings make a range of applications possible, including cellular and in vivo imaging, as well as reporting on local electromagnetic near-field properties of complex nanostructures.