A Golgi Apparatus-Targetable Probe Based on Lanthanide Complexes for Ratiometric Time-Gated Luminescence Detection of Hydrogen Sulfide

Development of bioanalytical methods for selective and accurate detection of H2S in living samples is essential for understanding the pathological and physiological functions of this gasotransmitter in biological systems. Here we report a Golgi apparatus-targetable lanthanide complex-based luminescent probe, Golgi-ABTTA-Eu3+/Tb3+, that can be used for accurately determining H2S in aqueous solution and living cells via the ratiometric time-gated luminescence (RM-TGL) technique. This probe is composed of 2,2 ':6 ',2 ''-terpyridine-Eu3+/Tb3+ mixed complexes as the luminophore, 4-azidobenzyl-ether as the responsive moiety, and sulfanilamide as the Golgi apparatus-targeting moiety. Upon reaction with H2S, accompanied by the cleavage of 4-azidobenzyl group from the probe molecule, the long-lived emission of Tb3+ complex at 540 nm is significantly enhanced, while that of Eu3+ complex at 610 nm is obviously reduced. It was noted that the I-540/I-610 ratio increased by 8.8 times after the probe was exposed to H2S, which enabled H2S to be detected with RM-TGL method. After being incubated with living cells, the probe molecules were selectively accumulated in the Golgi apparatus, which allowed H2S in the Golgi apparatus to be successfully imaged in RM-TGL mode.