It remained challenging to fabricate Tb^(3+)-doped lanthanide nanocrystals(NCs)to simultaneously acquire strong energy migration upconversion(EMU)emissions of Tb^(3+)while suppressing the Tm3+UV upconversion emissions...It remained challenging to fabricate Tb^(3+)-doped lanthanide nanocrystals(NCs)to simultaneously acquire strong energy migration upconversion(EMU)emissions of Tb^(3+)while suppressing the Tm3+UV upconversion emissions that cause background biofluorescence issues in bioapplications based on Tb^(3+)-doped EMU NCs.Herein,we report a novel sandwich structured core@shell@shell scheme for the design of EMU NCs,for example,NaLuF4∶Yb/Gd@NaGdF4∶Tm@NaLuF4∶Tb NCs,wherein Yb^(3+),Tm^(3+),and Tb^(3+)are incorporated separately into the inner core,middle shell,and outer shell,respectively.We found that in the sandwich structured NCs,the effective inter-shell energy transfer from Gd^(3+)in the middle shell to Tb^(3+)in the outer shell accelerated the Yb^(3+)-Tm^(3+)five-photon upconversion and the subsequent Tm^(3+)to Gd^(3+)energy transfer processes,which could eventually lead to almost complete inhibition of Tm^(3+)UV upconversion emissions,concurrent with the strong EMU emissions of Tb^(3+).Our findings might stimulate new concepts for manipulating upconversion emissions of lanthanide NCs.展开更多
基金supported by the Science and Technology Cooperation Fund between Chinese and Australian Governments(grant no.2017YFE0132300)the Strategic Priority Research Program of the CAS(grant no.XDB20000000)+1 种基金the National Natural Science Foundation of China(grant nos.21771185,U1805252,12074380,12074379,and 21975257)the CAS/SAFEA International Partnership Program for Creative Research Teams.
文摘It remained challenging to fabricate Tb^(3+)-doped lanthanide nanocrystals(NCs)to simultaneously acquire strong energy migration upconversion(EMU)emissions of Tb^(3+)while suppressing the Tm3+UV upconversion emissions that cause background biofluorescence issues in bioapplications based on Tb^(3+)-doped EMU NCs.Herein,we report a novel sandwich structured core@shell@shell scheme for the design of EMU NCs,for example,NaLuF4∶Yb/Gd@NaGdF4∶Tm@NaLuF4∶Tb NCs,wherein Yb^(3+),Tm^(3+),and Tb^(3+)are incorporated separately into the inner core,middle shell,and outer shell,respectively.We found that in the sandwich structured NCs,the effective inter-shell energy transfer from Gd^(3+)in the middle shell to Tb^(3+)in the outer shell accelerated the Yb^(3+)-Tm^(3+)five-photon upconversion and the subsequent Tm^(3+)to Gd^(3+)energy transfer processes,which could eventually lead to almost complete inhibition of Tm^(3+)UV upconversion emissions,concurrent with the strong EMU emissions of Tb^(3+).Our findings might stimulate new concepts for manipulating upconversion emissions of lanthanide NCs.
