The Y3(AI,Ga)5O12:Ce^3+,Cr^3+,Nd^3+(YAGG)nano-phosphors with homogeneous particle-size distribution,low aggregation and average crystalline size of about 65 nm were obtained using a modified Pechini method.Only slight...The Y3(AI,Ga)5O12:Ce^3+,Cr^3+,Nd^3+(YAGG)nano-phosphors with homogeneous particle-size distribution,low aggregation and average crystalline size of about 65 nm were obtained using a modified Pechini method.Only slight aggregation of the crystallites occurs after post-annealing at 1100℃.The intense Ce^3+bands in the excitation spectra of the Ce^3+,Cr^3+,Nd^3+co-doped materials monitoring the Cr^3+emission at 690 nm indicate energy transfer from Ce^3+to Cr^3+.Weak Nd^3+lines are observed,as well.In addition,the emission of Nd^3+at 1060 nm with excitation of Ce^3+and Cr^3+confirms the Ce^3+/Cr^3+to Nd^3+energy transfer.The short average luminescence decay times for the Ce^3+emission indicate the Ce^3+/Cr^3+to Nd^3+energy transfer.Eventually,the Y3(AI,Ga)5O12:Ce^3+,Cr^3+,Nd^3+nano-phosphors exhibit persistent luminescence originating from the 4f^3→4f^3 transitions of Nd^3+which matches well to the first biological window to be used in bioimaging applications.展开更多
Near-infrared （NIR） persistent-luminescence nanoparticles have emerged as a new class of background-free contrast agents that are promising for in vivo imaging. The next key roadblock is to establish a robust and co...Near-infrared （NIR） persistent-luminescence nanoparticles have emerged as a new class of background-free contrast agents that are promising for in vivo imaging. The next key roadblock is to establish a robust and controllable method for synthesizing monodisperse nanoparticles with high luminescence brightness and long persistent duration. Herein, we report a synthesis strategy involving the coating/etching of the SiO2 shell to obtain a new class of small NIR highly persistent luminescent ZnGa2O4：Cr^3＋,Sn^4＋（ZGOCS） nanoparticles. The optimized ZGOCS nanoparticles have an excellent size distribution of -15 nm without any agglomeration and an NIR persistent luminescence that is enhanced by a factor of 13.5, owing to the key role of the SiO2 shell in preventing nanoparticle agglomeration after annealing. The ZGOCS nanoparticles have a signal-to-noise ratio -3 times higher than that of previously reported ZnGa204：Cr^3＋ （ZGC-1） nanoparticles as an NIR persistent-luminescence probe for in vivo bioimaging. Moreover, the persistent-luminescence signal from the ZGOCS nanoparticles can be repeatedly re-charged in situ with external excitation by a white light- emitting diode; thus, the nanopartides are suitable for long-term in vivo imaging applications. Our study suggests an improved strategy for fabricating novel high-performance optical nanoparticles with good biocompatibility.展开更多
基金Project supported by Polish National Science Centre(Project:OPUS11#2016/21/B/ST5/02385)
文摘The Y3(AI,Ga)5O12:Ce^3+,Cr^3+,Nd^3+(YAGG)nano-phosphors with homogeneous particle-size distribution,low aggregation and average crystalline size of about 65 nm were obtained using a modified Pechini method.Only slight aggregation of the crystallites occurs after post-annealing at 1100℃.The intense Ce^3+bands in the excitation spectra of the Ce^3+,Cr^3+,Nd^3+co-doped materials monitoring the Cr^3+emission at 690 nm indicate energy transfer from Ce^3+to Cr^3+.Weak Nd^3+lines are observed,as well.In addition,the emission of Nd^3+at 1060 nm with excitation of Ce^3+and Cr^3+confirms the Ce^3+/Cr^3+to Nd^3+energy transfer.The short average luminescence decay times for the Ce^3+emission indicate the Ce^3+/Cr^3+to Nd^3+energy transfer.Eventually,the Y3(AI,Ga)5O12:Ce^3+,Cr^3+,Nd^3+nano-phosphors exhibit persistent luminescence originating from the 4f^3→4f^3 transitions of Nd^3+which matches well to the first biological window to be used in bioimaging applications.
文摘Near-infrared （NIR） persistent-luminescence nanoparticles have emerged as a new class of background-free contrast agents that are promising for in vivo imaging. The next key roadblock is to establish a robust and controllable method for synthesizing monodisperse nanoparticles with high luminescence brightness and long persistent duration. Herein, we report a synthesis strategy involving the coating/etching of the SiO2 shell to obtain a new class of small NIR highly persistent luminescent ZnGa2O4：Cr^3＋,Sn^4＋（ZGOCS） nanoparticles. The optimized ZGOCS nanoparticles have an excellent size distribution of -15 nm without any agglomeration and an NIR persistent luminescence that is enhanced by a factor of 13.5, owing to the key role of the SiO2 shell in preventing nanoparticle agglomeration after annealing. The ZGOCS nanoparticles have a signal-to-noise ratio -3 times higher than that of previously reported ZnGa204：Cr^3＋ （ZGC-1） nanoparticles as an NIR persistent-luminescence probe for in vivo bioimaging. Moreover, the persistent-luminescence signal from the ZGOCS nanoparticles can be repeatedly re-charged in situ with external excitation by a white light- emitting diode; thus, the nanopartides are suitable for long-term in vivo imaging applications. Our study suggests an improved strategy for fabricating novel high-performance optical nanoparticles with good biocompatibility.
