A novel NIR fluorescent probe for in situ visualizing Fe(ii) and its application in drug-induced liver/kidney injury

Abstract

Fe²⁺ has high redox activity and participates in many important physiological processes in vivo, playing a crucial role in the living system. An excessive iron content can lead to oxidative stress and cell damage, leading to the occurrence of many diseases. Therefore, it is necessary to establish an effective method to detect unstable iron(II) ions (Fe²⁺). In this work, a novel NIR fluorescent probe MDJ-O for Fe²⁺ based on the N-oxide structure was explored. The probe can monitor Fe²⁺ based on the ICT mechanism. In the PBS buffer solution containing 1 mM CTAB, MDJ-O showed a rapid response toward Fe²⁺ in 5 min with a fluorescence enhancement of 49-fold (λ_ex/λ_em = 535/720 nm). The sensitivity of MDJ-O for Fe²⁺ was brilliant, and the detection limit was as low as 3.09 μM. Notably, MDJ-O was successfully utilized for living cell imaging and in vivo imaging of zebrafish and mice. In addition, MDJ-O was successfully used for monitoring the level changes of Fe²⁺ in the liver and kidney injuries induced by acetaminophen (APAP), achieving the visualization of the injury. This work is of great significance for the study of drug-induced liver and kidney injury and other iron-related diseases.