Construction of a Cu²⁺-Responsive NIR Fluorescent Probe and the Preliminary Evaluation of its Multifunctional Application

Cu²⁺ was deemed as toxic and the most common heavy metal pollution in the water and food. Meanwhile, endogenous Cu²⁺ was deeply involved in plenty of physiological and pathological processes of human. Cu²⁺ imbalance was related to multiple diseases. Here we developed a Cu²⁺-responsive NIR probe HX, which not only demonstrated obvious color change when subjected to Cu²⁺, but also showed linear-dependent NIR fluorescence emission to Cu²⁺ concentration for Cu²⁺ detection and quantification both in vitro and in vivo. When HX was applied to imaging Cu²⁺ in the cell or living animals, intracellular Cu²⁺ fluctuation and Cu²⁺ accumulation in the liver could be visualized to indicate the copper level in the cell or organs with low background signals. Meanwhile, by applying HX to monitor Cu²⁺ uptake in the tumor, copper transporter function could be evaluated to screen the patient who are sensitivity to platinum drug.