Multi-Photon Sensitized Excitation of Near Infrared Emitting Lanthanides

Abstract
Near infrared (NIR) multi-photon excitation of the NIR-emitting lanthanides neodymium (Nd3+) and ytterbium (Yb3+) sensitized by a fluorescein-linked chelator was demonstrated. Because tissues display minimal absorbance near the excitation wavelength of 800 nm, and because the lanthanides display long decay times, these results suggest the use of Nd3+ and Yb3+ as luminescent probes in tissues with multi-photon excitation.