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Sandwich magnetically imprinted immunosensor for electrochemiluminescence ultrasensing diethylstilbestrol based on enhanced luminescence of Ru@SiO2 by CdTe@ZnS quantum dots
摘要： A molecularly imprinted magnetic sensor with electroluminescent tags (MIP-ECL sensor) was developed for ultrasensing diethylstilbestrol (DES). A strategy is exploited to enhance ECL emission of the [Ru(bpy)3]2 +-tripropyl amine (TPrA) system by CdTe@ZnS quantum-dots (QDs) through energy transfer. Magnetically molecularly imprinted nanoparticles (MMIPs NPs) based on Fe3O4@SiO2 carriers are artificial, easily reproducible, and could replace easily inactivated first antibodies for capturing more DES molecules. Functionalized bio-conjugates of single antibody-CdTe@ZnS (Ab-CdTe@ZnS) are for the first time loaded on signal labels of Ru(bpy)3 2 +-doped silica nanocomposites (Ru@SiO2) for signal amplification. The final bio-conjugated signal probes are denoted as Ab-DES/CdTe@ZnS-Ru@SiO2. MMIPs beads that have captured antigens are bio-conjugated with antibody-labeled luminescent probes by specific immunoreactive reaction, and then the luminescent immunocomplex generates ECL signal on the magnetic electrode. The logarithm of ECL intensities depend linearly on the logarithm of DES concentrations in the range from 4.8×10? 4 to 36.0 nM with a detection limit of 0.025 pM. This novel assay is much more sensitive than other MIP sensors, and achieves lower cost and more enhanced stability than other immunosensors. The sensor is significantly potential and has been applied to DES detection in actual environment.
关键词： [Ru(bpy)3]2+-doped silica,Probe-mode ECL sensor,Core-shell QDs,Magnetically imprinted nanoparticles,Diethylstilbestrol,Single antibody sandwich-type
更新于2025-09-23 15:19:57
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Controllable photon energy deposition efficiency in laser processing of fused silica by temporally shaped femtosecond pulse: Experimental and theoretical study
摘要： Photon energy deposition plays a crucial role in femtosecond laser irradiation followed by chemical etching processing, which is an emerging technique for the better control of micro/nano structures on fused silica. In this study, we have experimentally and theoretically studied the controllable photon energy deposition in laser irradiation of fused silica by temporally shaped femtosecond laser pulse trains. The experimental result shows that the photon energy deposition efficiency could be either reduced or enhanced by adjusting the total fluence of shaped pulse trains. Furthermore, the sub-pulse interval and intensity ratio of temporally shaped pulse trains were revealed to play a critical role in photon energy deposition. The corresponding experimental observations are qualitatively explained by a plasma model that considers the free electron generation processes and corresponding feedback on the photon energy deposition.
关键词： Photon energy deposition,Femtosecond laser,Temporally shaped pulse,Chemical etching,Fused silica
更新于2025-09-23 15:19:57
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Influence of wavelength on the bandwidth of W-type plastic-clad silica optical fibers
摘要： The bandwidth and steady-state loss of multimode W-type plastic-clad silica optical fibers are investigated by solving the time-dependent power flow equation. The results show how the bandwidth of W-type plastic-clad silica optical fibers can be enhanced by shifting from the red to the infrared wavelength region for different intermediate layer widths and refractive indices of the outer cladding. Such characterization of these fibers is consistent with their manifest effectiveness in reducing modal dispersion and increasing bandwidth.
关键词： steady-state loss,power flow equation,bandwidth,infrared wavelength region,W-type plastic clad silica optical fiber
更新于2025-09-23 15:19:57
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Thin silica-based microsheets with controlled geometry
摘要： A high demand for materials with defined geometry and size is required in a wide range of fields. Inorganic compounds, especially silica-based, arise as a cheap source and chemically flexible for the purpose. Silica display unique properties, like easy functionalization and good optical to manipulate. In this work, we developed a method to create thin silica microsheets with defined size and high-fidelity shape using superhydrophobic-hydrophilic microarrays. These microstructures were produced through sol-gel process using biomimetic superhydrophobic surfaces decorated with wettable spots. The results confirm the manufacture of porous silica microstructures with defined design (squares and circles) and thickness around 7 μm. The methodology applied in this work enables the high throughput fabrication of shaped silica materials in a single step, unlocking an extensive number of applications in areas that require miniaturization, like microelectronics or in fields like sensing and biomedicine.
关键词： Silica microsheets,High-fidelity shape,Inorganic materials,High throughput,Sol-gel process
更新于2025-09-23 15:19:57
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Glutathione- and light-controlled generation of singlet oxygen for triggering drug release in mesoporous silica nanoparticles
摘要： A combined stimuli-responsive photosensitiser and drug release system based on mesoporous silica nanoparticles was prepared. This nanoplatform encapsulated molecules of a zinc(II) phthalocyanine substituted with a glutathione-cleavable 2,4-dinitrobenzenesulfonate quencher and doxorubicin linked via a singlet-oxygen-cleavable 9,10-dialkoxyanthracene linker. In the presence of glutathione (in mM range) and upon irradiation (λ > 610 nm), the phthalocyanine units were activated by detaching from the quenching component to emit fluorescence and generate singlet oxygen. The latter subsequently cleaved the 9,10-dialkoxyanthracene linker to trigger the release of a doxorubicin derivative. The glutathione- and light-controlled activation and drug-release processes on this nanoplatform were demonstrated in phosphate buffered saline. The activation in fluorescence emission by intracellular thiols was also shown inside HepG2 human hepatocellular carcinoma cells. Upon irradiation, the nanosystem exhibited high cytotoxicity due to the photodynamic effect of the activated phthalocyanine units, but the cytotoxic effect of the released Dox moieties was not notable probably due to their reduced cytotoxicity as a result of the pendant substituent and the low drug loading in the nanoparticles.
关键词： mesoporous silica nanoparticles,photosensitiser,photodynamic therapy,doxorubicin,drug release,glutathione,singlet oxygen
更新于2025-09-23 15:19:57
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Preparation of triplea??responsive porous silica carriers and carbon quantum dots for photodynamica??chemo therapy and cell multicolor imaging
摘要： Photosensitive carbon quantum dots (CQDs) provide a new route to treat cancer owing to their ability to produce singlet oxygen. In this paper, pH/redox/enzyme-responsive porous silica-based carriers with CQDs were constructed for photodynamic-chemical combination therapy. Porous silica (pSiO2) sample presents uniform sphere with center-radial channels, which is favorable for drug loading and delivery. The CQDs with size of 2.5 nm were synthesized and have the excellent ability to generate singlet oxygen. After loading CQDs and drug molecules, the channels of pSiO2 carrier were blocked with hyaluronic acid (HA)/chitosan (CHI) layer. The disulfide bonds conjugating HA to the surface of pSiO2 carrier would achieve redox-responsive drug release while breaking disulfide bonds and HA/CHI layer could endow the pSiO2 carrier enzyme/pH responsive drug release. The prepared pSiO2 carriers display low cytotoxicity and good biocompatibility for multicolor imaging and photodynamic-chemo therapy.
关键词： CQDs,photodynamic-chemical combination therapy,controlling release,porous silica
更新于2025-09-23 15:19:57
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Recent Advances in Silica Glass Optical Fiber for Dosimetry Applications
摘要： In this paper, we review the highly promising silica glass, fabricated as doped and undoped optical fiber for intended use in radiation dosimetry. The dosimetry techniques reviewed here, underpinned by intrinsic and extrinsic defects in silica glass, focus on Thermoluminescence (TL), Optically Stimulated Luminescence (OSL) and Radioluminescence (RL), with occasional references to the much more established Radiation Induced Attenuation (RIA). The other focus in this review is on the various materials that have been reported earlier as dopants and modifiers used in silica glass optical fiber radiation dosimeters. This article also elaborates on recently reported optical fiber structures, namely, cylindrical fibers, photonic crystal fibers and flat fibers, as well as dimensions and shapes used for optimization of dosimeter performance. The various types of optical fiber radiation dosimeters are subsequently reviewed for various applications ranging from medical dosimetry such as in external beam radiotherapy, brachytherapy and diagnostic imaging, as well as in industrial processing and space dosimetry covering a dynamic dose range from μGy to kGy. Investigated dosimetric characteristics include reproducibility, fading, dose response, reciprocity between luminescence yield to dose-rate and energy dependence. The review is completed by a brief discussion on limitations and future developments in optical fiber radiation dosimetry.
关键词： radioluminescence,thermoluminescence,Silica optical fiber,review,dosimetry
更新于2025-09-23 15:19:57
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Encapsulation of Dual Emitting Giant Quantum Dots in Silica Nanoparticles for Optical Ratiometric Temperature Nanosensors
摘要： Accurate temperature measurements with a high spatial resolution for application in the biomedical fields demand novel nanosized thermometers with new advanced properties. Here, a water dispersible ratiometric temperature sensor is fabricated by encapsulating in silica nanoparticles, organic capped PbS@CdS@CdS “giant” quantum dots (GQDs), characterized by dual emission in the visible and near infrared spectral range, already assessed as efficient fluorescent nanothermometers. The chemical stability, easy surface functionalization, limited toxicity and transparency of the silica coating represent advantageous features for the realization of a nanoscale heterostructure suitable for temperature sensing. However, the strong dependence of the optical properties on the morphology of the final core–shell nanoparticle requires an accurate control of the encapsulation process. We carried out a systematic investigation of the synthetic conditions to achieve, by the microemulsion method, uniform and single core silica coated GQD (GQD@SiO2) nanoparticles and subsequently recorded temperature-dependent fluorescent spectra in the 281-313 K temperature range, suited for biological systems. The ratiometric response—the ratio between the two integrated PbS and CdS emission bands—is found to monotonically decrease with the temperature, showing a sensitivity comparable to bare GQDs, and thus confirming the effectiveness of the functionalization strategy and the potential of GQD@SiO2 in future biomedical applications.
关键词： silica shell,QD functionalization,nanothermometers,optical sensor,ratiometric sensing
更新于2025-09-23 15:19:57
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Spectroscopic studies of silica-incorporated lanthanum ?2-diketonate complexes for application in optoelectronic devices
摘要： In the present research work, silica-incorporated complexes of lanthanum β-diketonate were synthesized. Structural characterization of the prepared complexes was made on the basis of FTIR and FESEM studies. Shifting of peaks in the FTIR spectra are discussed in relation with the complexation, also incorporation of silica in complexes was confirmed by the FTIR spectra. FESEM and EDX studies were performed to know the surface morphology as well as elemental composition of the prepared complexes. The optical properties such as diffuse reflectance and photoluminescence were studied to get the idea about the possible transitions among the energy levels of the complexes as well as to know the emission peaks. The assignment of luminescence band is determined from excited state lifetime. The variation in luminescence intensity with time was measured by recording decay curves at fixed emission wavelength. The life time for all the three complexes was measured in micro-second (μs) order. Color coordinates of the complexes lie in the blue region. Thermal stability of the complexes was checked by measuring the loss in weight as a function of temperature.
关键词： FESEM,silica-incorporated lanthanum β-diketonate,FTIR,thermal stability,photoluminescence
更新于2025-09-23 15:19:57
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Top-hat and Gaussian laser beam smoothing of ground fused silica surface
摘要： Laser smoothing is a promising technique for processing optical glass due non-contact characteristics and easy-adaptability to non-spherical surfaces. The smoothing effects of CO2 laser of top-hat and Gaussian intensity on ground fused silica surfaces were examined in the work. The results show that ground surface with surface micro-roughness of 500 nm (RMS) can be smoothed to < 0.5 nm (RMS) with both intensity profiles. Best surface roughness rises with increasing power density of laser and therefore lower power density combined with slow scanning speed is favored to improve surface quality. Numerical model was established to investigate thermal and hydrodynamic transient process to elucidate the underlying mechanism. Simulations show that smoothing process takes place at the same time as the temperature rises due to ever-decreasing viscosity of fused silica. Beam shaping is able to reduce peak power density of high power processing laser and smoothing efficiency might be increased without the loss of the processed quality of glass.
关键词： Laser smoothing,Roughness,Top-hat beam,Gaussian beam,Fused silica,Laser polishing
更新于2025-09-23 15:19:57