Azide and sulfonylazide functionalized fluorophores for the selective and sensitive detection of hydrogen sulfide

Abstract

[EN] Three fluorescent probes (1–3) for the selective and sensitive detection of hydrogen sulfide have been synthesized and characterized. Probe 1 is a coumarin derivative functionalized with an azide moiety whereas 2 contain the azide reactive group into a naphthalene fluorophore backbone. Probe 3 is composed also by a naphthalene fluorophore but, in this case, functionalized with a sulfonylazide reactive moiety. Probes 1 and 3 are non-fluorescent whereas 2 is weakly emissive in HEPES (10 mM, pH 7.4)–DMSO 99:1 (v/v). The emission behavior of the three probes was tested against selected anions, bio-thiols and oxidant molecules. Of all the chemical species tested, only HS− is able to induce an enhancement in the emission intensity (50, 11 and 20-fold for 1, 2 and 3, respectively). The observed emission in the presence of hydrogen sulfide is ascribed, in the case of probes 1 and 2, to an azide–amine reduction induced by HS− anion, whereas for probe 3 the sensing mechanism is related with a sulfonylazide–sulfonamide conversion. The three probes are very sensitive to HS− anion with limits of detection of 0.17, 0.20 and 0.40 mM for 1, 2 and 3 respectively. Cell viability studies demonstrated that 1–3 probes are essentially non-toxic at concentrations 10–50 μM and are well suited for in vivo studies. Finally, probe 1 was used for the detection on intracellular HS− anion in HeLa cells by means of confocal microscopy. ; Financial support from the Spanish Government (Project MAT2012-38429-004-01) and the Generalitat Valenciana (Project PROMETEO/2009/016) is gratefully acknowledged. S.E. is grateful to the Generalitat Valenciana for his Santiago Grisolia fellow. C.T. also thanks the Ministerio de Ciencia e Innovacion for her FPU grant. L.E.S.F. thanks the Carolina Foundation and UPNFM-Honduras for his doctoral grant. ; El Sayed Shehata Nasr, S.; De La Torre Paredes, C.; Santos Figueroa, LE.; Marín Hernández, C.; Martínez Mañez, R.; Sancenón Galarza, F.; Costero Nieto, AM. (2015). Azide and sulfonylazide functionalized ...