title: Accurate thermometry based on the red and green fluorescence intensity ratio in NaYF4: Yb, Er nanocrystals for bioapplication.
abstract: A biological temperature measurement method based on the fluorescence intensity ratio (FIR) was developed to reduce uncertainty. The upconversion luminescence of NaYF4:Yb, Er nanocrystals was studied as a function of temperature around the physiologically relevant range of 300-330 K. We found that the green-green FIR Fe and red-green FIR (I660/I540) varied linearly as temperature increased. The thermometric uncertainties using the two FIRs were discussed and were determined to be almost constant at 0.6 and 0.09 K for green-green and red-green, respectively. The lower thermometric uncertainty comes from the intense signal-to-noise ratio of the measured FIRs owing to their comparable fluorescence intensities.
authors.forename: Lixin
authors.initials: L
authors.lastname: Liu
authors.forename: Feng
authors.initials: F
authors.lastname: Qin
authors.forename: Tianquan
authors.initials: T
authors.lastname: Lv
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Zhang
authors.forename: Wenwu
authors.initials: W
authors.lastname: Cao
mesh_terms: D004871:Erbium / Q000737:chemistry; D005453:Fluorescence; D049449:Luminescence; D053758:Nanoparticles / Q000737:chemistry*; D059629:Signal-To-Noise Ratio; D013696:Temperature; D062125:Thermometry / Q000379:methods*; D015018:Ytterbium / Q000737:chemistry; D015019:Yttrium / Q000737:chemistry
chemical_list: D015019:Yttrium; D004871:Erbium; D015018:Ytterbium