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.