A series of mono-dispersed hexagon NaGdF_4:Yb^(3+),Er^(3+)@NaGdF_4 core-shell nanoparticles with different shell thickness were synthesized via a co-precipitation method. Nanoparticles with high upconversion fluoresce...A series of mono-dispersed hexagon NaGdF_4:Yb^(3+),Er^(3+)@NaGdF_4 core-shell nanoparticles with different shell thickness were synthesized via a co-precipitation method. Nanoparticles with high upconversion fluorescent emissions result in large signal-to-noise ratio, which guarantees the accuracy of the sensitivity. Besides, the maximum sensitivity of these NPs as detection film increases first and then decreases with the shell thickness increasing. When the shell thickness is 2.3 nm(NaGdF_4-2), the maximum sensitivity(0.69959 ppm^(-1)) is reached. A large degree of overlap between the rhodamine B absorption band and the Er^(3+) green emission bands ensures that the NaGdF_4:Yb^(3+),Er^(3+)@NaGdF_4 nanoparticles can be used as fluorescent probe to detect the concentration of rhodamine B based on fluorescent intensity ratio technology. The linear relationship between the rhodamine B concentration and the intensity ratio(R) of green and red emission intensity(I_(S+H) and I_F) were studied systematically. The result shows that the maximum sensitivity can be obtained in low concentration rhodamine B(<4 ppm), which is lower than the reported minimum detection concentration. Thus, the ultra-high sensitivity detection by NaGdF_4:Yb^(3+),Er^(3+)@NaGdF_4 core-shell upconversion nanoparticles in low concentration can be realized,which provides promising applications in bio-detection filed.展开更多
基金supported by the National Natural Science Foundation of China(61565009,11664022)the Foundation of Natural Science of Yunnan Province(2016FB088)+2 种基金the Reserve Talents Project of Yunnan Province(2017HB011)the Young Talents Support Program of Faculty of Materials Science and Engineering,Kunming University of Science and Technology(14078342)Scientific and Technological Research Program of Chongqing Municipal Education Commission(KJ1711277)
文摘A series of mono-dispersed hexagon NaGdF_4:Yb^(3+),Er^(3+)@NaGdF_4 core-shell nanoparticles with different shell thickness were synthesized via a co-precipitation method. Nanoparticles with high upconversion fluorescent emissions result in large signal-to-noise ratio, which guarantees the accuracy of the sensitivity. Besides, the maximum sensitivity of these NPs as detection film increases first and then decreases with the shell thickness increasing. When the shell thickness is 2.3 nm(NaGdF_4-2), the maximum sensitivity(0.69959 ppm^(-1)) is reached. A large degree of overlap between the rhodamine B absorption band and the Er^(3+) green emission bands ensures that the NaGdF_4:Yb^(3+),Er^(3+)@NaGdF_4 nanoparticles can be used as fluorescent probe to detect the concentration of rhodamine B based on fluorescent intensity ratio technology. The linear relationship between the rhodamine B concentration and the intensity ratio(R) of green and red emission intensity(I_(S+H) and I_F) were studied systematically. The result shows that the maximum sensitivity can be obtained in low concentration rhodamine B(<4 ppm), which is lower than the reported minimum detection concentration. Thus, the ultra-high sensitivity detection by NaGdF_4:Yb^(3+),Er^(3+)@NaGdF_4 core-shell upconversion nanoparticles in low concentration can be realized,which provides promising applications in bio-detection filed.
