Abstract Eu 2+ /Mn 2+ ‐co‐doped white‐emitting Ca 5 (PO 4 ) 3 F phosphors have been synthesized by a combustion‐assisted synthesis method. The PXRD patterns confirmed the single‐phase fluorapatite crystal structure for all the samples independently of their substitution level. Their luminescence properties reveal that the developed phosphors can efficiently convert UV light in a broad range from 250 to 420 nm into tunable white emission. Based on the luminescence spectra and fluorescence decay curves, we can confirm that energy transfer from the Eu 2+ to Mn 2+ ions takes place in the Ca 5 (PO 4 ) 3 F:Eu 2+ ,Mn 2+ phosphors, and that the energy‐transfer efficiency increases with increasing Mn 2+ content. The emission colors of the obtained phosphors can be tuned from blue to white and eventually to yellow by controlling the doping content of the Eu 2+ and Mn 2+ ions. These results suggest that these phosphors are potential single‐component white‐light phosphors for n‐UV‐pumped white LEDs.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Luminescence properties of Sr8(Mg,Zn)La(PO4)7:Eu2+ phosphors were investigated by changing the content of Zn substitution. The Zn substitution was confirmed to change the crystallinity and luminescence properties of the phosphors. A eutectic mixture of two iso-structural compounds from Sr8MgLa(PO4)7 and Sr8ZnLa(PO4)7 are hosts for Eu2+ activator ions, allowing for carefully tuning the various parameters associated with efficient solid state white lighting. The phosphors exhibit systematically varied hues from yellow toward white and eventually to blue and the relative intensity of yellow and blue emissions can be adjusting the concentration of Zn2+, respectively. The Eu2+ activated Sr8(Mg,Zn)La(PO4)7 phosphor has potential applications as a UV radiation-converting phosphors for white LEDs.
Cancer imaging with minimal background signal and targeted intracellular drug delivery are of vital importance in clinical cancer diagnosis and therapy. Herein, we developed a biomimetic nanoprobe for activated fluorescence imaging and targeted drug delivery. pH-responsive porous coordination polymer nanoparticles (PCP NPs) were first synthesized by a codeposition method, anticancer drug doxorubicin (DOX) was then loaded into PCP NPs through physical and electrostatic adsorption (PCP-DOX), and finally the cell membranes extracted from Bel-7402 cancer cells were coated on the DOX-loaded PCP NPs (PCP-DOX-CM). The fluorescence of DOX was quenched due to the fluorescence resonance energy transfer between DOX and PCP NPs. Under acidic environment inside cancer cells, PCP NPs degraded, DOX was released from PCP-DOX-CM, and the fluorescence of DOX was activated, which was very specific for cancers with a high signal-to-noise ratio. Benefited from immune escaping and homologous targeting ability from cancer cell membranes, compared with PCP-CM and PCP-DOX, PCP-DOX-CM significantly enhanced the cellular endocytosis of DOX in Bel-7402 cancer cells and exhibited excellent cancer therapy effect in vitro. Together, our work provides a useful platform for an activated cancer imaging system and personalized cancer treatment.
Uniform Mn-doped alkaline-earth metal tungstate—AWO4 (A = Ca, Sr, Ba)—nanorods of reproducible size, shape, and composition have been methodically prepared using a modified template-directed methodology under ambient, room-temperature conditions. The dopant ion distribution within the nanostructures does not appear to adversely affect either the structural or crystalline integrity of our as-prepared compounds, as determined by microscopy and diffraction studies. What is much more important is the fact that the presence of Mn2+ not only substantially increases the photoluminescent potential of a pristine tungstate material but also reinforces its versatility by adding a desirable magnetic component to its repertoire of properties. In so doing, we have created multifunctional one-dimensional nanorods with exciting opto-magnetic behavior, which should become important for the future incorporation of these materials into functional nanoscale devices, with various potential applications in a number of diverse fields.
MicroRNAs (miRNAs) play important roles in the regulation of target gene expression and cell development. Therefore, developing of accurate and visual detection methods for miRNAs is important for early diagnosis of cancer. In this study, we established a visual detection method for miRNA 155 based on DNAzyme amplification strategy in living cells. MnO2 nanosheets were employed to deliver locked DNAzyme and substrate DNA into cells. The gold nanoparticle (AuNP) probe was taken up by cells autonomously. Then, MnO2 nanosheets were reduced to Mn2+ by glutathione in cells and DNA modules were released. MiRNA 155 took away locker DNA by strand displacement reaction to activate the DNAzyme. Then, the DNAzyme cleaved the substrate DNA and released single-stranded DNA named key DNA. Then, Key DNA hybridized with the hairpin DNA, making cy5 far away from AuNP and turning on its fluorescence. One target miRNA led to plenty of released key DNA when lots of substrate DNA was added. Thus, the visual detection of miRNA 155 in living cells would be initiated. Under confocal laser microscopy, the fluorescence was obviously observed in tumor cells but not in normal cells. The method has a linear range from 0.1 to 10 nM and a low detection limit of 44 pM on in vitro detection.
In this work, a multifunctional theranostic nanoprobe (Au-Ag-HM) was skillfully designed for simultaneous imaging of intracellular reactive oxygen species (ROS) and caspase-3 activity. The Au-Ag-HM was fabricated by coloading of silver nanoparticles (AgNPs) and hematoporphyrin monomethyl ether (HMME) to Au nanoflowers (AuNFs). When Au-Ag-HM was devoured by cancer cells, HepG2 cells were used as the model, and under laser irradiation, the photogenerated intracellular ROS by the photosensitizer HMME would induce the apoptosis of cancer cells. Meanwhile, the intracellular ROS triggered the oxidative etching of AgNPs on Au-Ag-HM, which led to a tremendous localized surface plasmon resonance response and scattering color changes in Au-Ag-HM, allowing in situ dark-field imaging of the ROS level in cancer cells. On the other hand, the ROS-induced activation of cellular caspase-3, which cleaved the C-peptide-containing caspase-3-specific recognition sequence (DEVD) and allowed HMME to release from the nanoprobe, resulted in a significant fluorescence recovery related to caspase-3 activity. Both photogenerated ROS and enhanced caspase-3 activity contributed to the synergistic effect of laser-mediated chemotherapy and photodynamic therapy. Therefore, the as-prepared theranostic probe could be used for simultaneous detection of cellular ROS and caspase-3 activity, distinguishing between tumor cells and normal cells, inducing the apoptosis of cancer cells, and providing a new method for diagnosis and therapy of cancer.
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