Ryszczyńska Sylwia, Martín Inocencio R, Grzyb Tomasz
Department of Rare Earths, Faculty of Chemistry, Adam Mickiewicz University, Poznań, Uniwersytetu Poznańskiego 8, 61-614, Poznan, Poland.
NanoBioMedical Centre, Adam Mickiewicz University, Poznań, Wszechnicy Piastowskiej 3, 61-614, Poznan, Poland.
Sci Rep. 2023 Sep 8;13(1):14819. doi: 10.1038/s41598-023-42034-z.
Recently, materials revealing the upconversion (UC) phenomenon, which is a conversion of low-energy photons to higher-energy ones, have attracted considerable attention in luminescence thermometry due to the possibility of precise and remote optical thermal sensing. The most widely studied type of luminescent thermometry uses a ratiometric approach based on changes in the UC luminescence intensity, mainly of lanthanide ions' thermally coupled energy levels. In this work, NaYF:Ho@NaYF and NaYF:Ho, Er@NaYF nanoparticles (NPs) were synthesized by the controlled reaction in oleic acid and octadecene at 573 K. The obtained nanoparticles had hexagonal structures, oval shapes, and average sizes of 22.5 ± 2.2 nm and 22.2 ± 2.0 nm, respectively. The spectroscopic properties of the products were investigated by measurements of the UC emission under 1151 nm laser excitation in the temperature range between 295 to 378 K. The sample doped with Ho and Er ions showed unique behavior of enhancing emission intensity with the temperature. The relative sensitivity determined for the NPs containing Ho and Er ions, reached the maximum value of 1.80%/K at 378 K. Here, we prove that the NaYF:Ho, Er@NaYF system presents unique and excellent optical temperature sensing properties based on the luminescence intensity ratios of the near-infrared bands of both Ho and Er ions.
最近，揭示上转换（UC）现象的材料，即低能量光子转换为高能量光子的现象，由于具有精确和远程光学热传感的可能性，在发光测温领域引起了相当大的关注。研究最广泛的发光测温类型采用基于上转换发光强度变化的比率法，主要是镧系离子的热耦合能级。在这项工作中，通过在油酸和十八烯中于573 K进行控制反应，合成了NaYF:Ho@NaYF和NaYF:Ho,Er@NaYF纳米颗粒（NPs）。所获得的纳米颗粒具有六边形结构、椭圆形形状，平均尺寸分别为22.5±2.2 nm和22.2±2.0 nm。通过在295至378 K温度范围内1151 nm激光激发下对上转换发射进行测量，研究了产物的光谱性质。掺杂Ho和Er离子的样品表现出随温度增强发射强度的独特行为。含Ho和Er离子的纳米颗粒的相对灵敏度在378 K时达到最大值1.80%/K。在此，我们证明NaYF:Ho,Er@NaYF体系基于Ho和Er离子近红外波段的发光强度比呈现出独特且优异的光学温度传感特性。
