A NIR pH sensitive fluorescent strategy for ratiometric detection of reactive oxygen species and its application in the imaging of arthritis

Abstract

Inflammation, a common disease triggered by oxidative stress, could produce reactive oxygen species (ROSs) of high level in tissues with a wide pH range. However, non-invasive in vivo monitoring ROS in both acidic and alkaline tissues remains a great challenge. In this work, a novel pH sensitive fluorescent probe, Hcy-OH, for ratiometric detection and imaging of ROSs was developed, exhibiting specific response to different ROSs at varying pH values. Hcy-OH exhibited selectivity for ONOO- under acidic condition, ClO- under neutral condition and 1O2 under alkaline condition. Encouraged by the remarkable sensing performance, Hcy-OH was applied to visualize exogenous and endogenous ROSs cellularly, with responsive fluorescence and ratiometric profile for indication. This sensing scheme was proved to be workable for inflamed tissue imaging, confirming its application for accurate monitoring of arthritis at organism level. The elaborate receptor Hcy-OH could serve as a powerful tool to reveal the relationship between the physiology and pathology of inflammation.