A water-soluble near-infrared (NIR) fluorescence activation probe for efficient detection of dissolved carbon dioxide

A near-infrared (NIR) fluorescent “turn-on” probe is presented for dCO2 detection in aqueous medium. This probe is based on perylene bisimide-functionalized hyperbranched polyethylenimine (PBI-HPEI) polymer, which exhibits significant dCO2-sensitive NIR fluorescence via a known photoinduced electron transfer (PET) mechanism, because of the excimer emission of π–π stacked PBI fluorophores. It is characterized with facile synthesis, fast response, excellent water-solubility and wide linear detection concentration range. It is thus capable of detecting dCO2 even in real-world carbonated beverages and drinking water samples.