Recent advances on small-molecule fluorophores with emission beyond 1000 nm for better molecular imaging in vivo

In the second near-infrared channel (NIR-II, 1000-1700 nm), organic and inorganic fluorophores are designed with superior chemical/optical properties to provide real-time information with deeper penetration depth and higher resolution owing to the innate lower light scattering and absorption of the NIR-II imaging than conventional optical imaging. Among them, the small-molecule based fluorophores have been highlighted due to their desirable biocompatibility and favorable pharmacokinetics. In this review, we introduced the latest research progress of the rational design of small-molecule NIR-II fluorophores and their impressively biological applications including the NIR-II signal imaging, multimodal imaging and theranostic. (C) 2019 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.