Selective FRET nano probe based on carbon dots and naphthalimide-isatin for the ratiometric detection of peroxynitrite in drug-induced liver injury

Drug-induced liver injury (DILI) is the most common cause for acute liver failure in the USA and Europe. However, most of DILI cases can recover or be prevented if treatment by the offending drug is discontinued. Recent research indicates that peroxynitrite (ONOO⁻) can be a potential indicator to diagnose DILI at an early stage. Therefore, the establishment of an assay to detect and track ONOO⁻ in DILI cases is urgently needed. Here, a FRET-based ratiometric nano fluorescent probe CD-N-I was developed to detect ONOO⁻ with high selectivity and excellent sensitivity. This probe consists of carbon dots and a naphthalimide-isatin peroxynitrite sensing system assembled based on electrostatic interactions. Using CD-N-I we were able to detect exogenous ONOO⁻ in live cells and endogenous ONOO⁻ in APAP-induced liver injury of HepG2 cells.