Eu3+- doped alumino-phosphate glass for ratiometric thermometer based on the excited state absorption

Very few devices are capable to measure temperature with high precision and sensitive, mainly in the micro and nanoscale. It is known that for biological applications it is required high sensitivity devices in a short temperature range (288-323 K). Recent reports are proposing the use of ratiometric thermometers based in the luminescence of trivalent lanthanide ions. In this paper, the ratiometric thermometer characteristic was investigated in an alumino-phosphate glass doped with Eu2O3. The studied temperature range was 288 - 333 K, and the material presents high sensitivity values (1.25-1.68% per K). The luminescence of Eu3+-doped alumino-phosphate glass does no present losses by energy transfer mechanism in this temperature range, making a quick predicable thermometric parameter by use of ratio between the integrated intensities of 5D0 → 7F2 and 5D0 → 7F0 transitions, respectively. Both excitation and emission are in wavelengths not strongly absorbed by living tissues, becoming promising material to applications in the laboratories scale, as the temperature measurements of cell cultures, and monitoring of tissues that does not require high penetration of excitation wavelengths.