A fluorescent probe based on novel fused four ring quinoxalinamine for palladium detection and bio-imaging

A fluorescent probe based on the Tsuji–Trost reaction was developed for detecting palladium species of all the typical oxidation states (0, +2, +4). In this probe, a novel fused four-ring quinoxalinamine was firstly designed as the fluorophore. The probe displayed high selectivity towards palladium with a distinct color change in aqueous media. Non-toxic and water-soluble PEG400 was used to replace the phosphine ligands and the reducing agents. In the absence of PEG400, the probe could discriminate Pd(0) from Pd(II) and Pd(IV) in solutions. The actual water sample detection and bio-imaging results indicated the probe's great potential for palladium detection in both solutions and living systems.