Water-soluble Cit-NaYbF₄:Tm³⁺with enhanced 802 nm emission by Sr²⁺ion doping forin vivofluorescence molecular tomography

Abstract

As a new type of optical imaging, fluorescence molecular tomography (FMT) has great potential in the field of biomedicine. However, current fluorescent probes still have some limitations which make in...

A low-temperature self-flux route to prepare hexagonal rare earth fluorides and manipulation of upconversion luminescence in rodlike NaYbF4:Tm3+/Fe3+ crystals

“…In the past several decades, considerable attention has been paid to ytterbium-based fluoride upconversion (UC) materials (including α-NaYbF 4 , β-NaYbF 4 , LiYbF 4 and KYb 2 F 7 ) with high levels of the most efficient sensitizer Yb 3+ due to some inherent outstanding physicochemical characteristics, including strong absorption for maximizing the utilization of near-infrared (NIR) pump photons owing to large absorption cross-sections (10 −20 cm −2 at ∼980 nm), only one excited manifold resulting in a lack of cross relaxation (CRs) between Yb 3+ ions, and its energy level transition being resonating well with the f-f transitions of the general rare earth activators (Er 3+ , Tm 3+ and Ho 3+ ), and thus generating efficient UC emissions. [1][2][3][4][5][6][7][8][9] As a consequence, ytterbium-based fluorides for constructing UC materials are believed to be promising substitutes for their distinctive yttrium (Y)-, lanthanum (La)-, gadolinium (Gd)-and lutetium (Lu)-based counterparts and to hold tremendous potential for applications in energy harvesting and conversion, sensors, and as biological labels and computed tomography contrast agents for multimodal bio-imaging. [1][2][3][4][5][6][7][8][9][10][11][12][13] Recently, Fe 3+ doping has attracted increasing interest based on the following aspects.…”

“…[1][2][3][4][5][6][7][8][9] As a consequence, ytterbium-based fluorides for constructing UC materials are believed to be promising substitutes for their distinctive yttrium (Y)-, lanthanum (La)-, gadolinium (Gd)-and lutetium (Lu)-based counterparts and to hold tremendous potential for applications in energy harvesting and conversion, sensors, and as biological labels and computed tomography contrast agents for multimodal bio-imaging. [1][2][3][4][5][6][7][8][9][10][11][12][13] Recently, Fe 3+ doping has attracted increasing interest based on the following aspects. [14][15][16][17][18][19][20][21][22] First and foremost, Fe 3+ is a low-cost, nontoxic and harmless trivalent non-rare-earth metal ion, which gives it considerable appeal in a great number of areas including energy storage, quantum information processing, classic data storage, magnetic resonance imaging and spin-controlled reactions.…”

“…1–9 As a consequence, ytterbium-based fluorides for constructing UC materials are believed to be promising substitutes for their distinctive yttrium (Y)-, lanthanum (La)-, gadolinium (Gd)- and lutetium (Lu)-based counterparts and to hold tremendous potential for applications in energy harvesting and conversion, sensors, and as biological labels and computed tomography contrast agents for multimodal bio-imaging. 1–13…”