Colloidal Rare Earth Vanadate Single Crystalline Particles as Ratiometric Luminescent Thermometers

Abstract

Thulium/ytterbium-doped yttrium vanadate particles provide a ratiometric thermal response as both colloids and powders via downshift or upconversion emissions. Here, we synthesized yttrium vanadates by controlled colloidal conversion of hydroxycarbonate precursors. A protected annealing process yielded single crystalline and readily dispersible particles that were manipulated individually by optical tweezers in water. Because individual particles displayed detectable emissions, this system has potential applications as a single-particle luminescent temperature sensor. Excitation on Yb3+ sensitizers (λexc = 980 nm) or at vanadate groups (λexc = 300 nm) resulted in Tm3+ emissions that effectively correlated with the temperature of the sample from 288 to 473 K with high relative thermal sensitivity (0.8–2.2% K–1), one of the highest reported for vanadate nanocrystals so far. Different pairs of Tm3+ transitions afford a ratiometric thermal response, which fitted common sensing requirements such as large [3F2,3 → 3H6 (λ = 700 nm)/1G4 → 3H6 (λ = 475 nm)] or small [3F2,3 → 3H6 (λ = 700 nm)/1G4 → 3F4 (λ = 650 nm)] spectral gaps and emission wavelengths at the first near-infrared biological window [3F2,3 → 3H6 (λ = 700 nm)/3H4 → 3H6 (λ = 800 nm)]. Our findings open new perspectives for the use of luminescent nanothermometers with controllable spatial localization, which is a remarkably interesting prospect to investigate microscopically localized events related to changes in temperature.

Bifunctional Tm3+,Yb3+:GdVO4@SiO2 Core-Shell Nanoparticles in HeLa Cells: Upconversion Luminescence Nanothermometry in the First Biological Window and Biolabelling in the Visible

“…The relative thermal sensitivity is defined as [1] stated in Equation 3: Figure 3c shows S rel calculated for our particles, with a value of 3.3% K −1 at 298 K. Since it depends on the ∆E value, that does not change substantially when changing the doping concentration, only a single value can be given for all the nanoparticles analyzed. The S rel values reported in the literature are between 1.0 and 28% K −1 , with most of the values being in the range 2.0-3.3% K −1 [34][35][36][37][38][39][40]. The value we report here for Tm,Yb:GdVO 4 @SiO 2 nanoparticles is the highest reported up to now in the literature for Tm 3+ -doped systems, only surpassed by that of Tm:NaYbF 4 @SiO 2 nanoparticles, although in that case, the maximum thermal relative sensitivity has been found at 100 K, far away from the biological range of temperatures.…”

Terras Raras: Tabela Periódica, Descobrimento, Exploração No Brasil E Aplicações

“…Nesse sentido, o campo da nanotermometria óptica utilizando a luminescência de íons lantanídeos é um campo em crescente ascensão, não apenas com a utilização de LOFs, mas também de nanopartículas sólidas e coloidais, com uma imensa gama de aplicações para o sensoriamento térmico em nanoescala. [154][155][156][157][158] Além das aplicações como materiais luminescentes, as TR são fundamentais no campo dos materiais magnéticos. Atualmente, os magnetos de Nd 2 Fe 14 B oferecem uma melhor relação potência-peso na indústria de ímãs e ainda mais alta eficiência na conversão de energia elétrica em energia mecânica em motores, ou vice-versa em geradores.…”

On the Fly” Characterization of YbIII:ErIII Co-Doped Upconversion Nanoparticle Nonlinear Optical Response from Single-Particle Trajectories

“…In addition to ensemble measurements, assessing the nonlinear optical response at the singleparticle level enables further studies relating structure to property, since UCNP nanoparticle composition and morphology influence upconversion emission intensities. Recently, single UCNP power dependence studies performed by optical trapping measurements have been reported [16], which enabled characterization of the nonlinear optical properties of individual nanoparticles and comparison with ensemble measurements. In the work described in reference [16], the authors varied the intensity of the trapping laser beam while monitoring UCNP emission to record their power dependence.…”

“…Recently, single UCNP power dependence studies performed by optical trapping measurements have been reported [16], which enabled characterization of the nonlinear optical properties of individual nanoparticles and comparison with ensemble measurements. In the work described in reference [16], the authors varied the intensity of the trapping laser beam while monitoring UCNP emission to record their power dependence.…”