Temperature Sensing Using Fluorescent Nanothermometers

Abstract

Acquiring the temperature of a single living cell is not a trivial task. In this paper, we devise a novel nanothermometer, capable of accurately determining the temperature of solutions as well as biological systems such as HeLa cancer cells. The nanothermometer is based on the temperature-sensitive fluorescence of NaYF(4):Er(3+),Yb(3+) nanoparticles, where the intensity ratio of the green fluorescence bands of the Er(3+) dopant ions ((2)H(11/2) --> (4)I(15/2) and (4)S(3/2) --> (4)I(15/2)) changes with temperature. The nanothermometers were first used to obtain thermal profiles created when heating a colloidal solution of NaYF(4):Er(3+),Yb(3+) nanoparticles in water using a pump-probe experiment. Following incubation of the nanoparticles with HeLa cervical cancer cells and their subsequent uptake, the fluorescent nanothermometers measured the internal temperature of the living cell from 25 degrees C to its thermally induced death at 45 degrees C.

Optically stimulated heating using Nd3+ doped NaYF4 colloidal near infrared nanophosphors

“…4 (a) [29]. Temperature sensing has been addiotionally achieved with the Er/Yb:NaYF 4 system due to relative changes of the green Er 3+ luminescence spectra shapes [30]. This feature has been rationalized by thermal Boltzman population of the well-defined energy levels.…”

Infrared‐Emitting QDs for Thermal Therapy with Real‐Time Subcutaneous Temperature Feedback

“…Spectral ratio [1] CaF2:Er,Yb 920 655 1.6 25-50 Spectral ratio [2] CdSe/ZnS QDs <525 620 0.7 10-80 Intensity [3] Gold Nanoclusters 580 710 0.5 15-45 Fluorescence lifetime [4] Green fluorescent protein 473 530 0.7 20-60…”

“…[1] A great variety of nanoparticles (NPs) with different functionalities, including imaging, temperature sensing, drug delivery or therapy have been fabricated and applied successfully at both the cellular and small animal level. [2] One of the therapeutic applications of NPs is thermal therapy of cancer, which consists in the destruction of malignant tumors by subjecting them to high temperatures for a certain amount of time.…”

Optical temperature sensing by upconversion luminescence of Er doped Bi5TiNbWO15ferroelectric materials

“…Over the past decades, the upconversion (UC) luminescence of rare-earth (RE) have attracted considerable attention in the fields of physics, chemistry, material science and life science because of their wide application such as color displays, 1 short-wavelength lasers, 2 IR quantum counter detectors, 3 optical sensing, 4 optical communications, 5 and biomedical diagnostics. 6 Recently, to achieve larger depth range in tissue and animal imaging, many efforts have been devoting to the development of optical monitoring devices by UC emission.…”

“…13 Some successful applications on the FIR technique by Er 3+ doped materials have been investigated. 4,[14][15][16][17] Most of the recent study interest relevant to the host materials was focused on the fluoride glasses due to the low phonon energy of the crystal lattice. 18,19 Nevertheless, less attention has paid to the host of Aurivillius bismuth layered-structure ferroelectrics (BLSFs).…”