Brites Carlos D S, Martínez Eduardo D, Urbano Ricardo R, Rettori Carlos, Carlos Luís D
Physics Department and CICECO-Aveiro Institute of Materials, University of Aveiro, Aveiro, Portugal.
"Gleb Wataghin" Institute of Physics (IFGW), University of Campinas (UNICAMP), Campinas, Brazil.
Front Chem. 2019 Apr 18;7:267. doi: 10.3389/fchem.2019.00267. eCollection 2019.
Luminescent nanothermometry uses the light emission from nanostructures for temperature measuring. Non-contact temperature readout opens new possibilities of tracking thermal flows at the sub-micrometer spatial scale, that are altering our understanding of heat-transfer phenomena occurring at living cells, micro electromagnetic machines or integrated electronic circuits, bringing also challenges of calibrating the luminescent nanoparticles for covering diverse temperature ranges. In this work, we report self-calibrated double luminescent thermometers, embedding in a poly(methyl methacrylate) film Er- and Tm-doped upconverting nanoparticles. The Er-based primary thermometer uses the ratio between the integrated intensities of the I and I transitions (that follows the Boltzmann equation) to determine the temperature. It is used to calibrate the Tm/Er secondary thermometer, which is based on the ratio between the integrated intensities of the H (Tm) and the I (Er) transitions, displaying a maximum relative sensitivity of 2.96% K and a minimum temperature uncertainty of 0.07 K. As the Tm/Er ratio is calibrated trough the primary thermometer it avoids recurrent calibration procedures whenever the system operates in new experimental conditions.
发光纳米测温法利用纳米结构的发光来测量温度。非接触式温度读数为在亚微米空间尺度上追踪热流开辟了新的可能性，这正在改变我们对发生在活细胞、微电磁机器或集成电路中的热传递现象的理解，同时也带来了校准发光纳米颗粒以覆盖不同温度范围的挑战。在这项工作中，我们报告了自校准双发光温度计，它嵌入在聚甲基丙烯酸甲酯薄膜中，含有铒和铥掺杂的上转换纳米颗粒。基于铒的主温度计利用(I)和(I)跃迁的积分强度之比（遵循玻尔兹曼方程）来确定温度。它用于校准基于(H)（铥）和(I)（铒）跃迁积分强度之比的铥/铒次温度计，显示出最大相对灵敏度为(2.96%\ K)，最小温度不确定度为(0.07\ K)。由于铥/铒比率通过主温度计进行校准，因此每当系统在新的实验条件下运行时，它都避免了反复的校准程序。
