tBased on the intramolecular charge transfer (ICT) fluorescence quenching mechanism, a ready-to-usecolorimetric coumarin coordinative probe has been designed and successfully achieved for the efficientdetection of Pd2+in aqueous buffer media (pH 7.0), which promisingly meets real-world challengesthrough a facile synthetic route, fast response, by-eye visualization, regenerative-action, high selectivityand sensitivity. The UV–vis spectra, mass spectra and density function theory studies have indicated thata 1:1 complex is formed between the probe and Pd2+. The detection limit of Pd2+is up to 2.9 × 10?7M.This reagent could even be used for estimation of Pd2+in samples with its known concentrations withconsiderable accuracy (ca. 4.1-4.8% error). Moreover, the binding affinity and fluorescence quenchingdegree of 1 with Pd2+are superior to those of 2. It has been demonstrated that the sensitive property ofthe chemosensors for Pd2+is highly dependent on the fine structure of the conjugated compounds.