Rational design of a highly effective cellulose-based macromolecular fluorescent probe for real-time recognition of palladium ion in environmental samples and its applications in plant and zebrafish.

Palladium ion (Pd) plays an important role in our daily life, but poses a great threat to the environment and human health. Thus, it is desirable to exploit a rapid and sensitive approach to realize the detection of Pd. In this study, a cellulose acetate-based macromolecular fluorescent probe CA-NA-PA was successfully prepared for tracking amounts of Pd. CA-NA-PA showed an obvious "on-off" fluorescence response to Pd, accompanied by the fluorescence color changed from bright yellow to colorless. CA-NA-PA had some outstanding detection performances such as low detection limit (26 nM), extremely short response time (1 min), good selectivity and anti-interference ability. Based on the advantages of probe mentioned above, CA-NA-PA could realize recognition of Pd concentration in environmental water and soil samples. What's more, the probe CA-NA-PA was applied to image Pd in zebrafish as well as in live onion tissue due to the good biocompatibility and cell membrane permeability of cellulose, suggesting its wide application prospect in biosystems.