Spying on the peroxynitrite fluctuation during hearing loss enabled by rationally designed fluorescent carbon dots

Hearing loss is a common type of sensory deprivation. Peroxynitrite (ONOO − ) is a biologically generated reactive oxygen species that can behave as a deleterious species due to its abnormal regulation associated with the pathogenesis of many human diseases, including hearing loss. Despite the importance of ONOO − and its biological functions, accurate detection methods for monitoring ONOO − in real time and exploring the roles of ONOO − in living systems are lacking. Herein, we report a novel carbon dots (CDs)-based fluorescence turn-on ONOO − probe for tracking endogenous and exogenous ONOO − produced by RAW264.7 cells. The probe exhibited considerably enhanced emission intensity, fast response rate, outstanding selectivity , and good sensitivity. Owing to these attractive sensing properties, peroxynitrite fluctuations in a hearing loss model were monitored for the first time. Therefore, CDs are potentially effective tools for assessing fluctuations in ONOO − under different physiological and pathological conditions.