Mathivanan, MoorthyMoorthyMathivananVillaman, DavidDavidVillamanShanmugaraj, KrishnamoorthyKrishnamoorthyShanmugarajSathish, MandaMandaSathishHaribabu, JebitiJebitiHaribabuMuena, Juan PabloJuan PabloMuenaNovoa, NestorNestorNovoa2026-07-072026-07-072026SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY, 346, 126908 (2026). https://doi.org/10.1016/j.saa.2025.1269081386-14251873-3557https://hdl.handle.net/20.500.12740/24732The development of multifunctional fluorescent organic materials capable of selective ion detection, subcellular targeting, and logical operations is a burgeoning area in chemical biology and materials science. Herein, we report the design and development of a novel acylhydrazone based fluorescent ligand (HSN & sdot;"Cl), which exhibits a distinct ""turn-on"" emission response toward Zn2+ ions and a subsequent ""turn-off"" response in the presence of sulfide ions (S2-). The molecular design incorporates structural elements that facilitate the ESIPT feature, conferring the probe with unique photophysical properties. This dual-responsive fluorescence ""off-on-off"" behaviour allows the construction of a molecular INHIBIT logic gate system. Further, the practical applicability of the probe was extended via fluorescent test strips for visual detection and bioimaging. The mitochondrial localization of HSN & sdot";"Cl was confirmed via co-staining experiments with MitoTracker red dye in live HeLa cells, demonstrating efficient accumulation in the organelle. Fluorescence microscopy further verified the capability of the probe for high-contrast imaging of intracellular Zn2+ ions distribution and its dynamic response to S2-ions."FluorescenceESIPTAcylhydrazoneMitochondriaEmission off-on-offINHIBIT logic gateArticulohttps://doi.org/10.1016/j.saa.2025.126908