|
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 |
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unique article identifier |
WOS:000322315600061
|
