Bioimaging: Illuminating the deep

Engineering non-toxic manganese-doped quantum dots have helped in overcoming the problem associated with a lack of imaging probes restricting the use of three-photon imaging enables deeper tissue penetration in vivo. Researchers have demonstrated the potential benefits of optical techniques for imaging diseased cells and tissues in live animals and patients. It has been speculated that optical imaging can color code the molecular variability and heterogeneity of diseased tissues in vivo, which could improve diagnostic accuracy and simplify image-guidance for surgical resection. The researchers show that the use of three-photon excitation of Mn-doped ZnS quantum dots can improve the imaging depth by a factor of two. This is achieved by redshifting the fluorescence of ZnS-quantum dots and excitation with a deep-penetrating near-IR 920-nm laser to reduce some of the optical interference from tissues.