Phosphinate-benzoindocyanin fluorescent probe for endogenous mitochondrial peroxynitrite detection in living cells and gallbladder access in inflammatory zebrafish animal models.

Potent oxidants such as peroxynitrite (ONOO) play important roles in the regulation of different physiopathological processes; their overproduction is thought to potentially cause several diseases in living organisms. Hence, the precise and selective monitoring of ONOO is imperative for elucidating its interplay and roles in pathological and physiological processes. Herein, we present a novel diphenyl phosphinate-masked benzoindocyanin "turn-on" fluorogenic probe to help detect mitochondrial ONOO in living cells and zebrafish models. A pale yellow color solution of BICBzDP turns rose-red upon the addition of ONOO selectively, contrary to that of other competitive bioactive molecules. BICBzDP displays an ultra-sensitivity detection limit (47.8 nM) with outstanding selectivity and sensitivity towards mitochondrial ONOO and possesses a notable 68-fold fluorescence enhancement involving a large redshift of 91 nm. Importantly, further biological experimental investigations with BICBzDP indicate specific sensitivity and reliability of the probe to track the ONOO level, not only in live cells, but also demonstrates dynamic fluctuations in the inflammatory zebrafish animal models. Thus, BICBzDP could be employed as a future potential biological tool for exploiting the role of ONOO in a variety of different physiological systems.