Rhodamine-modified upconversion nanophosphors for ratiometric detection of phosgene

Phosgene is a colorless nerve gas whose inhalation can cause respiratory and pulmonary injury, or even causing death. Phosgene is used widely in many industrial fields and in wars. Therefore, the timely and accurate detection of phosgene in industrial accidents and wars is very urgent. However, the traditional fluorescent chemosensor is limited for its need UV/visible light as the excitation source. Herein a new type of phosgene chemosensor based on fluorescent dyes and UCNPs was developed, which can be used to detect the concentration of phosgene through the change of its fluorescence intensity. This chemosensor is based on lanthanide-doped up-conversion nanomaterials (UCNPs) and fluorescent molecule that has an “off-on” response to phosgene upon the NIR excitation which makes it possible to detect the phosgene quickly and snugly in war. Moreover, this fluorescent detection allows quantitative detection of phosgene by ratiometric. First, we introduced the upconversion nanocrystal into the fluorescent chemosensor and developed a new NIR excited up-conversion detection of phosgene. Then this chemosensor have been characterized by NMR, FTIR and XRD. Finally, the selective sensitivity of the chemosensor to the detection of phosgene is obtained by its spectral changes.