New NIR-II dyes without a benzobisthiadiazole core

Fluorescent NIR-II imaging has a wide range of benefits not offered by other imaging modalities for biomedical applications, derived from its combination of high spatial and temporal resolution due to reduced photon absorption, scattering and tissue auto-fluorescence. Compared to the well-studied NIR-I small-molecule fluorophores, the structures of NIR-II fluorophores are scarce. To date, the main fluorophore units are composed of conjugated pi system with a benzobisthiadiazole (BBTD) core and donor-acceptor-donor (D-A-D) structure. Herein, researchers Yang et al. and Zhang et al. have reported new NIR-II probes ECX and FD-1080 respectively without a BBTD core which are highlighted. (C) 2018 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.