Fluorescent nanoprobe for in-vivo ratiometric imaging of endogenous hydrogen peroxide resulted from drug-induced organ damages.

Drug-induced organ damages have been considered as a grave problem regarding public health; hence effective method for in vivo detection of drug-induced organ damages is of great significance. Herein we developed a ratiometric fluorescent nanoprobe (NPs-A), which was prepared by loading the probe molecules into phospholipid bilayer, for assaying hydrogen peroxide (HO, an organ damage biomarker) level in vivo. The photophysical behavior of the probe molecule depends on the electron-withdrawing ability of the group at the 6- position of anthracene ring, on which the recognition moiety for hydrogen peroxide (dicarbonyl coupled with nitrophenyl, referred to as nitrophenyl-dicarbonyl) was introduced. Upon the reaction of the probe with HO, nitrophenyl-dicarbonyl group transforms into carboxyl group, and due to the variation of the electron-withdrawing ability of the 6th substituent, the fluorescent properties of the probe molecule alters accordingly, thus ensuring the ratiometric detection for HO with high selectivity with the detection limit of 0.49μM. In addition, the nanoprobe (NPs-A) was applied for cell and in vivo imaging applications; and the results indicate that it can detect and track the level of HO in living cells and to monitor and spatially map endogenous HO levels in a drug-induced organ damage model of zebrafish.