Standardizing luminescence nanothermometry for biomedical applications

Abstract

<p>Luminescence nanothermometry requires standardization for reliable and quantitative evaluation.</p>

Rational Design of Ratiometric Luminescence Thermometry Based on Thermally Coupled Levels for Bioapplications

“…Generally, the excitation power density used for the spectral measurement should be low enough to avoid the thermal effect, because serious laser‐induced heating effects would affect thermal calibration curve with weakened sensitivity through triggering the higher actual temperature around samples than the set environmental temperature. [ 28,138 ] For example, Maciel et al. increased the maximum S a value from 0.0056 to 0.007 K –1 in Er 3+ /Yb 3+ doped Y 2 SiO 5 powders via replacing continuous wave 975 nm laser excitation by a 5 ns pulsed laser excitation, which was attributed to the substantially eliminated optical heating effects of samples.…”

“…As the typical primary thermometer, the temperature could be determined based on simplest model of Boltzmann thermal equilibrium between two closely spaced thermally coupled levels (TCLs) from single emitting center, which overcomes the above‐mentioned limitation of secondary thermometers. [ 28,29 ] Therefore, the explorations of NIR light‐responsive phosphors as TCLs‐based ratiometric luminescence thermometers have recently gained growing attentions especially in biological field. [ 30–33 ] Above‐mentioned typical kinds of thermometers based on both contact and noncontact methods are depicted in Figure .…”

A Theoretical Framework for Ratiometric Single Ion Luminescent Thermometers—Thermodynamic and Kinetic Guidelines for Optimized Performance

“…Given the large number of possible electronic 4f n microstates of lanthanides, the flexibility in choice of a potential luminescent probe for luminescence thermometry appears unlimited if ∆E 21 is in the order of several k B T. Any inappropriate choice of a lanthanide ion for luminescence thermometry at a temperature of interest may in principle work, but at the cost of a low temperature sensitivity and thus, high temperature uncertainty. Critical reviews stressing the various experimental difficulties in achieving high precision and accuracy in luminescence thermometry have been recently published by the group of Jaque, [199,200] Dramićanin's book [201] and perspective [202] or by Bednarkiewicz et al [203] Despite the enormous amount of experimental data available in the literature of luminescence thermometry, a governing unifying theory that allows for a systematically driven search towards effective thermometers is still virtually non-existent. Only in the last few years, some progress towards this direction is recordable, which also resulted in the availability of applets and programs.…”

Facile modulation the sensitivity of Eu2+/Eu3+-coactivated Li2CaSiO4 phosphors through adjusting spatial mode and doping concentration

“…These results implied that the resultant compounds had good reversibility and stability. As disclosed in previous reports, the temperature uncertainty of the optical temperature sensor based on the luminescent compounds is able to be determined by means of following functions [42][43][44] : www.nature.com/scientificreports/ where I 1 refers to the emission intensity of Eu 2+ ions, I 2 stands for the emission intensities of the Eu 3+ ions originating from the 5 D 0 → 7 F J transitions, δI 1 and δI 2 are ascribed to the errors of I 1 and I 2 , respectively, and δT is the temperature uncertainty. Via these above expressions, the δT values were estimated to be 0.139-0.248 K (303-583 K), 0.146-0.352 K (303-583 K), 0.116-0.433 K (303-583 K), 0.102-0.383 K (303-583 K), respectively, when the combinations of Eu 2+ / 7 F 1 , Eu 2+ / 7 F 2 , Eu 2+ / 7 F 4 and Eu 2+ / 7 F J were employed.…”