Ratiometric highly sensitive luminescent nanothermometers working in the room temperature range. Applications to heat propagation in nanofluids
authors Brites, CDS; Lima, PP; Silva, NJO; Millan, A; Amaral, VS; Palacio, F; Carlos, LD
nationality International
journal NANOSCALE
keywords INTRACELLULAR TEMPERATURE; FLUORESCENCE LIFETIME; THERMAL-CONDUCTIVITY; THERMOMETRY; NANOPARTICLES; NANOCRYSTALS; NANOSCALE; SENSORS; MECHANISMS; RESOLUTION
abstract There is an increasing demand for accurate, non-invasive and self-reference temperature measurements as technology progresses into the nanoscale. This is particularly so in micro-and nanofluidics where the comprehension of heat transfer and thermal conductivity mechanisms can play a crucial role in areas as diverse as energy transfer and cell physiology. Here we present two luminescent ratiometric nanothermometers based on a magnetic core coated with an organosilica shell co-doped with Eu3+ and Tb3+ chelates. The design of the hybrid host and chelate ligands permits the working of the nanothermometers in a nanofluid at 293-320 K with an emission quantum yield of 0.38 +/- 0.04, a maximum relative sensitivity of 1.5% K-1 at 293 K and a spatio-temporal resolution (constrained by the experimental setup) of 64 x 10(-6) m/150 x 10(-3) s (to move out of 0.4 K - the temperature uncertainty). The heat propagation velocity in the nanofluid, (2.2 +/- 0.1) x 10(-3) m s(-1), was determined at 294 K using the nanothermometers' Eu3+/Tb3+ steady-state spectra. There is no precedent of such an experimental measurement in a thermographic nanofluid, where the propagation velocity is measured from the same nanoparticles used to measure the temperature.
publisher ROYAL SOC CHEMISTRY
issn 2040-3364
year published 2013
volume 5
issue 16
beginning page 7572
ending page 7580
digital object identifier (doi) 10.1039/c3nr02335d
web of science category Chemistry, Multidisciplinary; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied
subject category Chemistry; Science & Technology - Other Topics; Materials Science; Physics
unique article identifier WOS:000322315600061

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