Repetitive afterglow in zirconia by pulsed near-infrared irradiation toward biological temperature sensing

Abstract

Photoluminescence provides information about the surrounding environment. In this study, aiming to develop a non-invasive deep body-temperature sensing method, we investigated photoluminescence properties of afterglow zirconia (ZrO2) by pulsed near-infrared (NIR) light irradiation based on the biological temperature. Pulsed light irradiation produced optically stimulated luminescence, followed by afterglow, with the property of repeating 100 times or more. Furthermore, the basic principle of temperature measurement was demonstrated through afterglow decay curve measurements. The use of harmless ZrO2 as a sensing probe and NIR light, which is relatively permeable to living tissues, is expected to realize temperature measurements in the brain and may also facilitate optogenetic treatment.

Light Delivery, Acoustic Read‐Out, and Optical Thermometry Using Ultrasound‐Induced Mechanoluminescence and the Near‐Infrared Persistent Luminescence of CaZnOS:Nd3+

“…In this way, the decay constant p ( T ) and, finally, the trap depth Δ E were obtained. [ 51 ] Data are shown in Figure 4c,f. For pPL, a trap depth of Δ E pPL ∼ 0.170 eV is obtained, significantly lower than previously reported values estimated using general order kinetics ( i.e ., 0.623 eV and 0.652 eV for pPL of CaZnOS:Mn 2+ ,Pr 3+ and CaZnOS:Mn 2+ ,Ce 3+ ; [ 13 ] note that significantly higher emission lifetime was reported for these materials, too, around ≈45 s as compared to the current 15 s. For USML, the decay process appears to occur in two regimes, depending on applied acoustic power, i.e ., with Δ E low ∼ 0.203 eV when the acoustic power is below 3 W, and Δ E high ∼ 1.349 eV for higher US power.…”