Temperature Sensing Properties Of Rare Earth Doped NaYF₄ And Detection Of Functional Organic Molecules

Rare-earth doped upconversion nanoparticles(UCNPs)have been developed rapidly in the temperature sensor,electro-optic display,bioimaging,fluorescence probe and biosensor,due to the advantage of chemical stability,excellent optical properties,large anti-Stockes shift and so on.With the development of the rare earth doped UCNPs in the temperature sensor and fluorescence detection probe,more and more shortcomings were exposed.Thus,in this work the NaYF4 UCNPs doped with different rare earth ions were synthesized by NaYF4 as the host to study the temperature sensing properties and detect functional organic molecule.The main results are:(1)Different sizes of NaYF4:Er3+,Yb3+UCNPs were synthesized via a thermal decomposition method and the temperature sensing properties under different excitation wavelengths were studied.The results showed that the temperature sensing properties of NaYF4:Er3+,Yb3+UCNPs were unacted on particle sizes and excitation wavelengths.(2)NaYF4:Tm3+,Yb3+UCNPs were synthesized via a thermal decomposition method and the temperature sensing properties under 980 nm excitation were studied.The results showed that the temperature sensing properties of NaYF4:Tm3+,Yb3+UCNPs were better than NaYF4:Er3+,Yb3+UCNPs.(3)NaYF4:Er3+,Yb3+@NaYF4 UCNPs with different shell thickness were synthesized via a thermal decomposition method and modified with polyetherimide(PEI)to acquire amine groups.UCNPs-based luminescence resonance energy transfer system(LRET),as a fluorescence probe,was used to detect functional nitroaromatics under 980 nm excitation.(4)NaYF4:Tm3+,Yb3+@NaYF4 UCNPs were synthesized via a thermal decomposition method and modified with PEI as a fluorescence probe to detect functional curcuminiods based LRET system under 980 nm excitation wavelengths.