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 I₅₄₀/I₆₁₀ 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.