Rational design of a unique Palladium coordination polymer with distinctive fluorescence and its application for CO sensing in living zebrafish

Abstract Carbon monoxide (CO) is known as a highly toxic gaseous air pollution, and also act as a key small signaling molecule that plays an important role in living organisms. Therefore, the real-time tracking of CO is of great significance for further research on the role of CO in physiological activity. To this end, a unique Palladium coordination polymer (Pd-NA) based on fluorescent naphthalene derivatives is constructed and applied for imaging CO. Morphology study indicates that Pd-NA assembles into large stacked planar structure. Spectroscopic experiments show that Pd-NA can response to CO with remarkable fluorescence change, significant fluorescence enhancement is obtained at 510 nm with the addition of CO. Similar with spectral change, Pd-NA can response to exogenous and endogenous generated CO in HeLa cells with up to 10-fold florescence enhancement. Furthermore, Pd-NA exhibits excellent one-photon and two-photon fluorescence imaging capability of sensing CO in living zebrafish. Overall, the present work has afforded a new paradigm and demonstrated the feasibility of CO sensing in living organisms by a rational designed Palladium coordination polymer for the first time.