Design and Synthesis of an MOF Thermometer with High Sensitivity in the Physiological Temperature Range

Abstract

An important result of research on mixed-lanthanide metal-organic frameworks (M'LnMOFs) is the realization of highly sensitive ratiometric luminescent thermometers. Here, we report the design and synthesis of the new M'LnMOF Tb0.80Eu0.20BPDA with high relative sensitivity in the physiological temperature regime (298-318 K). The emission intensity and luminescence lifetime were investigated and compared to those of existing materials. It was found that the temperature-dependent luminescence properties of Tb0.80Eu0.20BPDA are strongly associated with the distribution of the energy levels of the ligand. Such a property can be useful in the design of highly sensitive M'LnMOF thermometers.

Sensing-functional luminescent metal–organic frameworks

“…In addition, some mixed lanthanide MOF containing ancillary ligands are also suitable for temperature sensing. 70 Cadiau 73 It is well-known that biological tissues have high permeability for the NIR emission because of their relative small adsorption or scatting. The NIR luminescent MOFs should thus have great potential for sensing temperature.…”

Wide‐range thermometry based on green up‐conversion luminescence of K3LuF6:Yb3+/Er3+ bulk oxyfluoride glass ceramics

“…Aiming at the development of optical thermometers with excellent temperature‐sensing properties, rare earth ions (REI)‐doped diverse fluorescent materials were characterized as optical thermometers, such as metal organic frameworks (MOFs), fluoride nanoparticles, ceramics, and glass . Among these REI, Er 3+ with 2 H 11/2 / 4 S 3/2 TCEL and applicable energy difference (~700 cm −1 ) has been widely applied in optical thermometry …”

“…Currently, among these materials mentioned above, the temperature‐sensing ability varies remarkably in different hosts . MOFs with insufficient stability generally restrict testing temperature to physiological temperature range . Fluorides possessing low phonon energy exhibit intense up‐conversion luminescence, which favors the accuracy of spectrum measurement and sensitivity .…”

“…6,10 Operating as "non-contact", such optical thermometry is particularly favorable for the temperature measurement in electromagnetically and thermal harsh environment, such as building fire detections, biological imaging systems, and micro/nanoscale temperature measurement. [11][12][13] Aiming at the development of optical thermometers with excellent temperature-sensing properties, rare earth ions (REI)-doped diverse fluorescent materials were characterized as optical thermometers, such as metal organic frameworks (MOFs), 4,14 fluoride nanoparticles, 5 ceramics, and glass. 1,15 Among these REI, Er 3+ with 2 H 11/2 / 4 S 3/2 TCEL and applicable energy difference (~700 cm À1 ) has been widely applied in optical thermometry.…”

Ratiometric near infrared luminescent thermometer based on lanthanide metal-organic frameworks

“…Recently, through the great variety of structural design, pore size control and post-synthetic modification, numerous MOFs with abundant and tunable luminescent properties have been prepared [17][18][19][20][21][22]. Among them, Lanthanide metal-organic frameworks (Ln-MOFs), with fast response and high sensitivity, have been explored and realized for functionalities and applications in display, sensing, and luminescent thermometers [23][24][25][26][27]. For example, the first ratiometric luminescent MOF thermometer, Eu 0.0069 Tb 0.9931 -DMBDC (DMBDC ¼2, 5-dimethoxy-1, 4-benzendicarboxylate) was synthesized.…”