Fluorescence Thermometers Involving Two Ranges of Temperature: Coordination Polymer and DMSP Embedding

The measurement of temperature is indispensable in the fields of life, science, and industry. Fluorescence thermometers are attractive to researchers because of their advantages such as noncontact, high sensitivity, fast response, and excellent anti-interference. Here, a new coordination polymer (HNU-76) was synthesized by assembling Zn²⁺ with the H₃TCA ligand, a fluorescent molecule with an AIE behavior, which can be used as a fluorescence thermometer. At 100-210 K, the fluorescence intensity ratio of HNU-76 versus temperature conforms to an Arrhenius-type decay relationship (R² = 0.997), which can be the candidate for low-temperature sensing. In order to increase the sensing range, 4-[4-(dimethylamino)styryl] pyndine (DMSP) was successfully embedded on HNU-76, obtaining HNU-76⊃DMSP. The fluorescence intensity of HNU-76⊃DMSP conforms to an Arrhenius-type decay relationship (R² = 0.997) at 270-360 K versus temperature. HNU-76 can be used for fluorescence detection at low temperatures, due to the DMSP loading, and HNU-76⊃DMSP can serve as the temperature thermometer in a range of temperatures common. Both materials show good cyclability and have the potential to be used in fluorescence thermometers.