Synthesis And Fluorescent Temperature Sensing Of Europium And Terbium Containing MOFs

Temperature is probably the most important parameter in every conceivable areas, such as materials science, biomedicine, energy science and industrial production. Traditional thermometers such as thermalcouple and mercury thermometer are used widely in scientific research and industrial production, but traditional contacting thermometers cannot meet the needs in some special conditions such as high-pressure, strong magnetic field, rapid response, large-scale imaging and contactless measurement.Aiming at these problems, many new temperature sensing materials have appeared in recent years, of which the fluorescent temperature-sensing materials have attracted great attention because of their fast response, high sensitivity, anti-electromagnetic interference and contactless measurement. These fluorescent temperature-sensing materials are mainly organic dyes, inorganic glass and inorganic-organic hybrid materials.Luminescent MOFs (metal-organic frameworks) are a new class of inorganic-organic hybrid optical functional materials. Rare earth metal luminescent MOFs have many advantages over rare earth metal complexes, such as predictable topologies, adjustable pore size and structure, stable structure and high luminous efficiency. The temperature-sensing principle of luminescent MOFs is based on the dependence of fluorescence intensity and lifetime on temperature.In this paper, EuDHBDC was designed and synthesized. The emission intensity of Eu3+quenching significantly when temperature increases, so EuDHBDC is a temperature sensitive material based on the intensity of Eu3+. This is because the triplet excited energy level of DHBDC is very close to the excited-state level of Eu3+, energy back transfer from Eu3+to DHBDC occurs when temperature increases, which results in the quenching of the emission intensity of Eu3+.The temperature probe based on single metal fluorescence intensity is easily affected by sensor concentration, excitation power, the drifts of lamp and detector Herein, a ratiometric thermometer Euo.043Tbo.957cpda based on ITb/IEu was designed and synthesized in this paper, which eliminate the affection of sensor concentration, excitation power, the drifts of lamp and detector, and self-calibration is achieved. Besides, Euo.043Tbo.957cpda has a wider temperature sensing range (40-300K) compared with Eu0.0069Tb0.9931-DMBDC. Many cellular metabolic pathways are regulated by temperature and pH, including signaling, cell death, ion transport. Therefore, it’s important to develop a bifunctional material to achieve temperature and pH sensing simultaneously. Herein, a Eu3+and Tb3+co-doped metal-organic frameworks Eu0.20sTb0.795dpda is synthesized, and Eu0.205Tb0.795dpda is sensitive for both temperature and pH in the range of biology.