Mito-Specific Ratiometric Terbium(III)-Complex-BasedLuminescent Probe for Accurate Detection of Endogenous Peroxynitriteby Time-Resolved Luminescence Assay

The level of peroxynitrite (ONOO−) is closely related to the pathogenesis of a series of diseases. Hence the accurate sensing of ONOO− is very important for a better understanding of its biological functions. Here, a time-resolved ratiometric nanoprobe (TD-DC) composed of energy donor unit (Tb(DPA)3) and energy receptor unit (DC) was designed. The response of TD-DC towards ONOO− in vitro was assessed by luminescence intensity and lifetime. The results demonstrated that TD-DC could precisely (39 nM) detect ONOO− with high selectivity and efficiency (29 s). TD-DC was further successfully employed in sensing endogenous ONOO− in A-375 cells. Besides, It could specifically localize in the mitochondrion where endogenous ONOO− mainly generated. The above results revealed that TD-DC is efficient and useful for real-time detection of ONOO− at sub-cellular levels.