A facile and effective method to prepare long-persistent phosphorescent nanospheres and its potential application for in vivo imaging

Abstract

In order to prepare new promising optical nanoprobes, long afterglow nanospheres with a narrow size distribution were successfully synthesized using mesoporous silica nanospheres (MSNs) both as morphology-controlling templates and the silicon source of long afterglow silicate. In our experiments, metal ions (Sr 2+ , Mg 2+ , Eu 3+ , Dy 3+ ) were impregnated into the pores of mesoporous silica nanospheres followed by high temperature calcination. The X-ray powder diffraction results show that SrMgSi 2 O 6 crystalline phase can be formed after calcination at 900 C for 3 h in a weakly reducing atmosphere and the as-prepared afterglow nanospheres have a nominal composition of SiO 2 /SrMgSi 2 O 6 :Eu 0.01 , Dy 0.02 . The field emission scanning electron microscopy results indicate that the as-prepared long afterglow silicate nanoparticles have spherical morphology with a narrow size distribution and their size can be tuned between 50 nm and 500 nm. Approximately 10 nm pores can be formed in the as-prepared nanospheres, certified by the transmission electron microscopy and BET analysis results. Long afterglow properties, ranging from 400 nm to 550 nm, peaking at 467 nm, can be observed from the asprepared nanospheres. After the surface was modified with amino groups, grafted by PEG-COOH and irradiated with 365 nm UV light for 10 min, the afterglow signal could be observed in real time for more than 1 h in a live mouse after peritoneal injection.

In Vivo Repeatedly Charging Near‐Infrared‐Emitting Mesoporous SiO2/ZnGa2O4:Cr3+ Persistent Luminescence Nanocomposites

“…[25] Briefly, 7 mL of ethanol, 0.2 g of CTAB, and 50 μL of diethanolamine were dissolved in 25 mL of water under stirring at 60 °C for 30 min to prepare a transparent solution. Then, 2 mL of tetraethoxysilane were added rapidly.…”

“…[ 24 ] We speculate that homogeneous distribution of these reactants in confi ned mesoporous nanostructures results in a higher reactivity than would otherwise be the case; such phenomena were observed previously. [25][26][27][28][29]…”

Near-infrared long-persistent phosphor of Zn3Ga2Ge2O10: Cr3+ sintered in different atmosphere

“…Since their emissions are in the region of the biologically transparent window (650-1100 nm) [12,13], moreover, since the emission lifetime is sufficiently long to permit late time-gated imaging, long persistent phosphors (LPPs) are unique and superior to other labels [14][15][16][17][18]. In such a case, auto-fluorescence from tissue organic components during imaging can be completely avoided, which gives rise to an extraordinary high signal-to-noise ratio [19,20].…”

A facile approach to upconversion crystalline CaF2:Yb3+,Tm3+@mSiO2 nanospheres for tumor therapy

“…The variation of surface area, pore volume and pore size is induced by the micelle aggregation of surfactant CTAB, which was reported in previous studies. 39, 40 In addition, it was found that, under the excitation using 980 nm NIR laser, three narrow-band emission peaks at ~ 478 nm, ~ 650 nm and ~ 800 nm presented for all three samples. (Fig.…”