| Temperature is an important parameter in human physiology and pathology. Most reaction processes between biological molecules in cells are affected by temperature. Compared with the traditional contact thermometers, such as thermocouple, mercurial thermometer, the luminescence-based temperature sensor have attracted wide attention for their advantages like non-contact, rapid response, high sensitivity, and applicable for fast moving objects and small size objects. The ratiometric luminescence thermometry makes the temperature sensing independent of the concentration and inhomogeneity of luminescent centers as well as the optoelectronic drifts of excitation source and detectors, thus can guarantee a precise temperature measurement. Therefore, it is unquestionable the research focus for temperature sensing.The near-infrared light has advantages like high detection depth, unaffected by the competing fluorescence frombiomatrices and less damage to the biological tissue, thus the lanthanide with near-infrared luminescence is introduced into a new kind of materials with outstanding designability characteristic:metal-organic frameworks. In this paper, three new dual lanthanide-organic frameworks are designed and synthesized, and their temperature sensing performance around physiological temperature are studied. The main research contents and results are as follows.In the paper, rare earth (Nd3+and Yb3+) ions and ligands H3BTC are used to prepare a series of lanthanide-organic framework LnBTC (Ln= ND, Yb, NdxYb1-x). The luminescent performance of LnBTC (Ln= Nd, Yb, NdxYb1-x) at room are explored, and the result shows that Nd0.054Yb0.946BTC simultaneously displays the characteristic emissions of the Nd3+ and Yb3+ ions when excited at 808 nm. The temperature dependence of photoluminescenee properties of Nd0.054Yb0.946BTC shows a perfect linear relationship between the INd/IYb ratio and temperature in the range of 288～323 K with sensitivity of 0.830～1.187% K-1, which can be applied in the physiological temperature sensing.H2BDC-F4 is used to synthesize a series of near-infrared luminescent lanthanide-organic framework LnBDC-F4(Ln= Nd, Yb, NdxYb1-x). The C-F has effectively weakened the quenching effect, thus the ligand can transfer energy to the lanthanide ions through "antenna effect". LnBDC-F4(Ln= Nd, Yb, NdxYb1-x) displays the characteristic emissions of the responding lanthanide ions when excited at 303 nm, Nd0.711Yb0.289BDC-F4 shows a linear relationship between the ratio and temperature in the range of 60～280 K, which can be applied in temperature sensing. Besieds, the Nano-Nd0.577Yb0.423BDC-F4 show a better linear relationship between the INd/lYb ratio and temperature in the range of 293～313 K with sensitivity of 0.967-1.201% K-1, which indicates it is an excellent luminescent thermometer.A new luminescence thermometry Nd0.866Yb0.134BTB with high sensitivity is synthesized by using H3BTB as ligand. Nd0.866Yb0.134BTB can be used for temperature sensing in the range of 303～333 K by using the linear relationship between the INd/IYb ratio and temperature, and its sensitivity (2.090～4.755%K-1) is much higher than that of Nd0.054Yb0.946BTC or Ndo.577Ybo.423BDC-F4. Besides, it is stable in H2O and PBS, and its biological toxicity is quite low, which means it has wide application prospect in cell temperature sensing. |
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