A novel alkyne compound as a Pd(II) fluorescent probe in aqueous medium and its bioimaging

Palladium is significant in chemistry, biology and environmental science, while as a toxic metal, it could have adverse effects on our health and the environment. It is thus critical to monitor the changes of Pd (II) in living cells. Here, we developed a new colorimetric and fluorometric probe (TP1) based on palladium(II)-involved reactivity. Compared with the reported Pd (II) sensors, TP1 was the first alkyne compound fluorescent probe with excellent water-solubility for Pd2+, which was via catalytic-depropargylation to form oxime for the detection of Pd2+ within a rapid response time 80 s. The detection limit of TP1 toward Pd(II) was estimated as 0.47 μM. In addition, the ability of the TP1 to detect Pd(II) in living cells (HepG2 cells) has been also proven. These results indicated that TP1 was a highly sensitive turn-off Pd(II) dye with promising biological applications.