Nitrobenzoxadiazole Ether-Based Near-Infrared Fluorescent Probe with Unexpected High Selectivity for HS Imaging in Living Cells and Mice.

Abstract

HS is an important endogenous gasotransmitter, and its detection in living systems is of great significance. Especially, selective and sensitive near-infrared (NIR) fluorescent HS probes with rapid response and large Stokes shift are highly desirable because of their superiority for in vivo detection. Probes with nitrobenzoxadiazole (NBD) ether as reaction sites have been well-explored recently to detect biothiols or HS/biothiols simultaneously, rather than to detect HS selectively. In this work, a new NBD ether-based NIR fluorescent probe was developed, which was unexpectedly found to show high selectivity for HS over various other analytes including biothiols, making it practical for specific detection of HS both in vitro and in vivo. Upon response to HS, this probe showed rapid and significant turn-on NIR emission changes centered at 744 nm within 3 min, together with a remarkable large Stokes shift (166 nm) and high sensitivity (LOD: 26 nM). Moreover, imaging exogenous and endogenous HS in living cells and rapid imaging of HS in living mice with this probe was successfully applied with excellent performance.