A new naphthalimide-Pd(II) complex as a light-up fluorescent chemosensor for selective detection of carbon monoxide in aqueous medium

A fluorescent light-up probe, MENap-Pd, was designed and synthesized to detect CO in aqueous buffer medium (pH 7.2, 37 °C). This detection was highly selective and sensitive towards CO. The probe prompted a more than 9-fold ‘turn-on’ fluorescence response to CO through the demetallation of the nonfluorescent Pd(II) complex, MENap-Pd to generate free fluorescent ligand, MENap in the reaction medium. The fluorescence response is highly selective towards relevant reactive oxygen, nitrogen, and sulfur species and also various cationic, anionic, and neutral species present in biological system. The limit of detection (LOD) of this probe for CO sensing (CORM-2) is calculated as 1.4 μM with a linear range of 0–60 μM concentration of CORM-2.