- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Up-Converting Lanthanide Fluoride Core@Shell Nanorods for Luminescent Thermometry in the First and Second Biological Windows - β-NaYF4: Yb3+, Er3+@SiO2 Temperature Sensor
摘要： Up-converting core@shell type β-NaYF4:Yb3+-Er3+@SiO2 nanorods have been obtained by a two-step synthesis process, which encompasses hydrothermal and microemulsion routes. The synthesized nanomaterial forms stable aqueous colloids and exhibits a bright dual-center emission (λex= 975 nm), i.e. up-conversion luminescence of Er3+ and down-shifting emission of Yb3+, located in the first (I-BW) and the second (II-BW) biological windows of the spectral range. The intensity ratios of the emission bands of Er3+ and Yb3+ observed in the Vis-NIR range monotonously change with temperature, i.e. the thermalized Er3+ levels (2H11/2→4I15/2/4S3/2→4I15/2) and the non-thermally coupled Yb3+/Er3+ levels (2F5/2→2F7/2/4I9/2→4I15/2 or 4F9/2→4I15/2). Hence, their thermal evolutions have been correlated with temperature using the Boltzmann type distribution and 2-th order polynomial fits for temperature sensing purposes, i.e. Er3+ 525/545 nm (max Sr = 1.31 %K-1) and Yb3+/Er3+ 1010/810 nm (1.64 %K-1) or 1010/660 nm (0.96 %K-1). Additionally, a fresh chicken breast was used as a tissue imitation in the performed ex vivo experiment, showing the advantage of the use of NIR Yb3+/Er3+ bands, vs. the typically used Er3+ 525/545 nm band ratio, i.e. better penetration of the luminescence signal through the tissue in the I-BW and II-BW. Such nanomaterials can be utilized as accurate and effective, broad-range Vis-NIR optical, contactless sensors of temperature.
关键词： Up-conversion luminescence,Luminescence intensity ratio (LIR),Functional nanomaterials,Rare earth ions,Energy transfer,Optical thermometer
更新于2025-11-25 10:30:42
-
Constructing new thermally coupled levels based on different emitting centers for high sensitive optical thermometer
摘要： In multi-emitting and thermochromic Bi3+-Tb3+-Eu3+ co-doped garnet type Ca3Sc2Si3O12 phosphor, new thermally coupled levels (New-TCLs) are firstly constructed based on 3P1(Bi3+)/5D0(Eu3+) and 5D4(Tb3+)/5D0(Eu3+). And the relative electron population of New-TCLs obeys similar Boltzmann type distribution rules owing to stronger thermalization process with the increase of temperature, which can be elaborated by steady-state rate equations. Hence, a novel self-calibrated non-invasion optical thermometer with high absolute/relative temperature sensitivities (0.094 K?1 at 498 K; 1.0% K?1 at 448 K) and good signal discrimination (Δλ ≈ 158 nm) can be achieved by taking advantage of fluorescence intensity ratio of such New-TCLs. This work exhibits a novel strategy to design high-performance optical thermometer in high temperature environment.
关键词： New thermally coupled levels,Thermalization,Optical thermometer,Fluorescence intensity ratio
更新于2025-09-12 10:27:22
-
A stoichiometric terbium-europium dyad molecular thermometer: energy transfer properties
摘要： The optical thermometer has shown great promise for use in the fields of aeronautical engineering, environmental monitoring and medical diagnosis. Self-referencing lanthanide thermo-probes distinguish themselves because of their accuracy, calibration, photostability, and temporal dimension of signal. However, the use of conventional lanthanide-doped materials is limited by their poor reproducibility, random distance between energy transfer pairs and interference by energy migration, thereby restricting their utility. Herein, a strategy for synthesizing hetero-dinuclear complexes that comprise chemically similar lanthanides is introduced in which a pair of thermosensitive dinuclear complexes, cycTb-phEu and cycEu-phTb, were synthesized. Their structures were geometrically optimized with an internuclear distance of approximately 10.6 ?. The sensitive linear temperature-dependent luminescent intensity ratios of europium and terbium emission over a wide temperature range (50–298 K and 10–200 K, respectively) and their temporal dimension responses indicate that both dinuclear complexes can act as excellent self-referencing thermometers. The energy transfer from Tb3+ to Eu3+ is thermally activated, with the most important pathway involving the 7F1 Eu3+ J-multiplet at room temperature. The energy transfer from the antenna to Eu3+ was simulated, and it was found that the most important ligand contributions to the rate come from transfers to the Eu3+ upper states rather than direct ligand–metal transfer to 5D1 or 5D0. As the first molecular-based thermometer with clear validation of the metal ratio and a fixed distance between the metal pairs, these dinuclear complexes can be used as new materials for temperature sensing and can provide a new platform for understanding the energy transfer between lanthanide ions.
关键词： temperature sensing,hetero-dinuclear complexes,lanthanide,energy transfer,optical thermometer
更新于2025-09-09 09:28:46