1. A novel high-sensitive upconversion thermometry strategy: Utilizing synergistic effect of dual-wavelength lasers excitation to manipulate electron thermal distribution
- Author
-
Yan Gao, Zeliang Ji, Yuansheng Wang, Yao Cheng, Jiaomei Wang, Xiangshui Cui, Hang Lin, and Ju Xu
- Subjects
Lanthanide ,Materials science ,02 engineering and technology ,Electron ,010402 general chemistry ,01 natural sciences ,law.invention ,law ,Materials Chemistry ,Electrical and Electronic Engineering ,Instrumentation ,business.industry ,Doping ,Metals and Alloys ,Atmospheric temperature range ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Laser ,Photon upconversion ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Excited state ,Optoelectronics ,0210 nano-technology ,business ,Excitation - Abstract
Conventional upconversion thermometry strategy, based on the thermally coupled levels (TCL) of lanthanide ions, confronts a dilemma in simultaneously achieving high absolute/relative temperature (T) sensitivities (Sa and Sr) and good signal discriminability. Herein, a novel thermometry strategy by utilizing the synergistic effect of dual-wavelength lasers to manipulate electron thermal distribution is proposed to go beyond the limitation of the TCL-based strategy. In the case of NaGdF4: 20%Yb3+, 2%Er3+ nanoparticles upon 980 & 1530 nm dual-excitation, it is found that more efficient utilization of excited photons results in a higher electron concentration in ladder-like energy levels of Er3+, owing to the diverse pumping routes, which increases transition rate of the T-dependent phonon-assisted cross-relaxation process, and in turn establishes a thermally-sensitive electronic connection between Er3+: 2H11/2,4S3/2 and Er3+: 4F9/2. Remarkably, not only a highest record value of Sa (0.0365 K−1) for the Er3+ doped host materials in the physiological temperature range (303–343 K) is achieved, but also a high Sr (1.29% K-1) and an excellent signal discriminability (Δλ = 112 nm) are obtained. Combining a much intensified upconversion (UC) signal and a good size/shape homogeneity in nanometer scale, the investigated NaGdF4: 20%Yb3+, 2%Er3+ upon dual-wavelength excitation is potentially applicable in the intracellular thermal sensing and imaging. This work exploits an effective way to develop high-performance T-sensors, and the proposed thermometry strategy can be extended to surges of the other lanthanide ions doped systems pumped by multiple-wavelength lasers.
- Published
- 2019