Decay time characteristics of La_2O_2S:Eu and La_2O_2S:Tb for use within an optical sensor for human skin temperature measurement

Abstract

This study is focused on the development of a remote temperature sensing technology, i.e. optical laser-based sensor, using thermographic phosphors for medical applications particularly within an electromagnetically hostile MRI (magnetic resonance imaging) environment. A MRI scanner uses a strong magnetic field and radio waves to generate images of the inside of the body. The quality of the image improves with increasing magnetic resonance, however, the drawback of applying a greater magnetic strength is the inducement of heat into the body tissue. Therefore, monitoring the patient's temperature inside MRI is vital but until now, a practical solution for temperature measurement did not exist.This paper shows Europium doped Lanthanum Oxysulphide and 4m o C -1 at 512nm and 538nm, respectively. In addition, La 2 O 2 S: Tb has a lower quenching rate of 4.19m o C -1 at 548nm due to its faster decay time.

Intense Red and Yellow Emissions from Sr[sub 2]SiO[sub 4]:Eu[sup 3+](Eu[sup 2+]) Electrospun Nanofibers

“…These are similar to those of the La 2 O 2 S:Eu 3+ phosphor and much shorter than those of the Zn 2 SiO 4 :Eu 3+ phosphor. 25,26 After calcining at 1000°C in a graphite crucible for 5 h, the excitation spectrum of Sr 2 SiO 4 :0.03 Eu electrospun nanofibers has Fig. 3a shows the amplified SEM image, and the scale bar is 1 m. ͑c͒ is the EDS spectrum of the nanofibers in Fig.…”

Temperature Sensing Using Fluorescent Nanothermometers

“…For example, the fluorophores NBD (7-nitrobenz-2-oxa-1,3-diazol-4-yl) and Laurdan (6-dodecanoyl-2-dimethylaminonaphthalene) have been reported to accurately determine the temperature of single living cells, and recently, a fluorescent hydrophilic nanogel was reported, which could determine intracellular temperatures within 0.5 °C . An alternative approach is to use Ln 3+ -doped fluorescent materials, which have shown the ability to act as thermal probes. − However, no studies of these Ln 3+ -based probes have been performed on liquids or on biological systems. The biological uses of Ln 3+ -doped nanoparticles (NPs) including FRET-based biosensors, in and ex vivo fluorescent imaging, as well as therapeutic applications such as photodynamic therapy have recently been demonstrated. − These NPs have attracted considerable attention since they possess the ability to emit light at higher energies than the excitation wavelengths (typically near-infrared).…”

Polymer-Encapsulated Phosphor Particles forIn VivoPhosphor Luminescence Applications

“…This could be explored. 4. A conventional approach for many biomedical applications involves a fiber optic probe in which light is delivered by a central fiber and return light is capture by optical fibers that surround the central fiber.…”

“…A variety of industries have taken advantage of phosphor thermometry and recently they have been investigated for biomedical applications as well [4]. The method makes use of phosphor materials identical or similar to many that are manufactured for lighting, display, scintillation, or medical X-ray applications.…”