- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Label-free immunosensors based on a novel multi-amplification signal strategy of TiO2-NGO/Au@Pd hetero-nanostructures
摘要： A label-free electrochemical immunosensor for quantitative detection of human epididymis specific protein 4 antigen (HE4 Ag) was developed by a novel multi-amplification signal system. The multi-amplification signal system was formed by loading bimetallic Au@Pd holothurian-shaped nanoparticles (Au@Pd HSs) on titanium oxide nanoclusters functionalized nitrogen-doped reduced graphene oxide (TiO2-NGO). The Au@Pd HSs were obtained via seed-mediated approach with in-situ grown palladium nanoarms on gold nanorods (Au NRs) surfaces, which possessed good electrocatalysis for hydrogen peroxide (H2O2) reduction and excellent biocompatibility. The TiO2-NGO with the high catalytic activity and large specific surface area was synthesized by hydrothermal method. Using H2O2 as an electrochemically active substrate, the prepared label-free electrochemical immunosensor based on the TiO2-NGO/Au@Pd HSs hetero-nanostructures as the signal amplification platform exhibited excellent selectivity, reproducibility and stability for the detection of HE4 Ag. Meanwhile, the linear range from 40 fM to 60 nM with the detection limit of 13.33 fM (S/N = 3) was obtained, indicating the immunosensor offers a promising method for clinical detection of HE4 Ag.
关键词： Au@Pd nanoparticles,Titanium oxide,Label-free electrochemical immunosensor,Nitrogen-doped reduced graphene oxide,Human epididymis specific protein 4
更新于2025-09-23 15:23:52
-
Polariton superregular breathers in a resonant erbium-doped fiber
摘要： We study polariton superregular (SR) breathers triggered by the resonant interaction of an optical field with two-level doping ions in an erbium-doped fiber. We demonstrate explicitly that the optical wave component always features a bright structure that describes the modulation instability (MI) development from localized small perturbations, while the SR matter-wave breathers exhibit more complicated dynamical evolution, which are absent in standard scalar SR breather theory. Despite the complexity, the exact link between these SR breathers and MI is established strictly by showing that the absolute difference of group velocities of SR breathers coincides exactly with the linear MI growth rate. In particular, we show how a small dip perturbation of the dark SR breather in the matter wave component induces an intriguing MI process of completely exponential decay. These results will enrich our understanding on the MI development in complex coupled light-matter interaction systems.
关键词： erbium-doped fiber,polariton,resonant interaction,modulation instability,superregular breathers
更新于2025-09-23 15:23:52
-
2.01～ 2.42 μm all-fiber femtosecond Raman soliton generation in a heavily germanium doped fiber
摘要： We demonstrated that an all-fiber system generates high-performance mid-infrared Raman solitons in a heavily germanium doped fiber (HGDF). A 10 m-long HGDF with a 12 μm core diameter and 64 mol.% GeO2 dopant is designed and pumped by a home-made 1.96 μm femtosecond fiber laser in the strong anomalous dispersion region. Stable and single-color Raman solitons are therefore obtained with a continuous wavelength tunability from 2.01 to 2.42 μm. The pulse duration of the mid-infrared Raman solitons can be as short as ~220 fs. The efficiency of energy transfer to a Raman soliton is about 32.5%, while the maximum average power, peak power and pulse energy are up to 27 mW, 3.6 kW and ~1 nJ, respectively. Different from previous multi-color Raman or supercontinuum-like generation from HGDFs pumped in the near-zero or normal dispersion regime, such pure mid-infrared Raman solitons exhibit excellent stability with a radio-frequency signal-to-noise ratio of ~60 dB. This is, to the best of our knowledge, the first demonstration of >2.4 μm stable Raman solitons in an all-fiber system. This work may pave a path towards compact and high-performance mid-infrared femtosecond fiber laser sources.
关键词： soliton self-frequency shift,Ultrafast fiber lasers,heavily germanium doped fiber,mid-infrared
更新于2025-09-23 15:22:29
-
Nickel Doping on Cobalt Oxide Thin Film Using by Sputtering Process-a Route for Surface Modification for p-type Metal Oxide Gas Sensors
摘要： This study proposes a route for surface modification for p-type cobalt oxide-based gas sensors. We deposit a thin layer of Ni on the Co oxide film by sputtering process and annealed at 350 °C for 15 min in air, which changes a typical sputtered film surface into one interlaced with a high density of hemispherical nanoparticles. Our in-depth materials characterization using transmission electron microscopy discloses that the microstructure evolution is the result of an extensive inter-diffusion of Co and Ni, and that the nanoparticles are nickel oxide dissolving some Co. Sensor performance measurement unfolds that the surface modification results in a significant sensitivity enhancement, nearly 200% increase for toluene (at 250 °C) and CO (at 200 °C) gases in comparison with the undoped samples.
关键词： Toluene,Co oxide thin film,Ni-doped,Gas sensor,RF sputtering,CO
更新于2025-09-23 15:22:29
-
Evaluation of Low-Temperature Saturation Velocity in β -(Al?Ga???)?O?/Ga?O? Modulation-Doped Field-Effect Transistors
摘要： We report on the high-field transport characteristics and saturation velocity in a modulation-doped β-(AlxGa1?x)2O3/Ga2O3 heterostructure. The formation of a 2-D electron gas (2DEG) in the modulation-doped structure was confirmed from the Hall measurements, and the 2DEG channel mobility increased from 143 cm2/V·s at room temperature to 1520 cm2/V·s at 50 K. The high electron mobility at 50 K made it feasible to achieve velocity saturation inside the channel. The saturation velocity was estimated based on both pulsed current–voltage measurements and small-signal radio frequency (RF) measurements. The measured velocity–field profile suggested a saturation velocity above 1.1 × 107 cm/s at 50 K. The small-signal RF characteristics were measured for the fabricated modulation-doped field-effect transistors with a Pt-based Schottky contact. The current gain cutoff frequency (ft) and maximum oscillation frequency (fmax) showed significant increases from 4.0/11.8 GHz at room temperature to 17.4/40.8 GHz at 50 K for the device with gate length of LG = 0.61 μm. The analysis of the low temperature ft based on device simulations indicated a peak velocity of 1.2 × 107 cm/s. The three-terminal off-state breakdown measurement further suggested an average breakdown field of 3.22 MV/cm. The high saturation velocity and high breakdown field in β-Ga2O3 make it a promising candidate for high-power and high-frequency device applications.
关键词： mobility,β-Ga2O3,modulation-doped field-effect transistor (MODFET),2-D electron gas (2DEG),saturation velocity,high breakdown field
更新于2025-09-23 15:22:29
-
Room-temperature ferromagnetism and morphology evolution of SnO2 flower-like microparticles by Zn-doping
摘要： We report on the growth of undoped and Zn-doped flower-like microparticles, which are constituted of SnO2 acicular nanoparticles (NPs) aggregated by one of their ends. NPs were synthesized by the hydrothermal method. The morphology of the NPs progressively changes from truncated rods to sharp needles by the effect of Zn doping. This morphology evolution is attributed to an increase of the surface free energy of the NPs' facets and to a modification of the growth front direction. Undoped samples exhibit a very low magnetization attributed to single positive charged oxygen vacancies, while Zn-doped samples exhibit ferromagnetic ordering due to Zn atoms in Sn substitutional positions (ZnSn). Thermal treatment under reducing atmosphere leads to the creation of an excess of VO conducting to a reduction of the magnetization, demonstrating that ferromagnetism in Zn-doped SnO2 NPs is attributed to ZnSn defects and to the octahedrally coordinated oxygen atoms.
关键词： Magnetization,Oxygen vacancies,SnO2 nanoparticles,Morphology,Zn-doped
更新于2025-09-23 15:22:29
-
A Visible Light-Near-Infrared Dual-Band Smart Window with Internal Energy Storage
摘要： The integration of electrochromic smart windows with energy storage is an appealing concept for green building development. Herein, we report a dual-band electrochromic energy storage (DEES) window capable of independent control of visible light (VIS) and near-infrared (NIR, solar heat) transmittance with a high internal charge storage. The key design feature is the use of composition-optimized Ta-doped nano-TiO2 nanocrystals as a multifunctional active material to deliver a high charge-storage capability concurrently with high bistability and long-cycle-life electrochromism in three distinct operating modes: (1) the VIS and NIR transparent "bright" mode; (2) the VIS transparent and NIR opaque "cool" mode; and (3) the completely opaque "dark" mode. The independent control of VIS (sunlight) and NIR (solar heat) modulation was successfully demonstrated in a DEES prototype with a high charge-storage capacity of 466.5 mA hr m?2 at 150 mA m?2 of current density.
关键词： nanocrystals,dual-band electrochromic,smart window,energy storage,Ta-doped TiO2
更新于2025-09-23 15:22:29
-
Thermal decomposition of bimetallic titanium complexes: A new method for synthesizing doped titanium nano-sized catalysts and photocatalytic application
摘要： In this study, synthesis of bimetallic (Co, Mn, and Ni) complexes of salicylic acid (L1) and 1,2 dihydroxybenzene (L2) based on titanium(IV) were investigated, then the samples were decomposed by thermal method to obtain MxTiyOz nanoparticles (M = Ni, Co, and Mn). The samples in complexes mode were analyzed by UV–Vis (200–800 nm), FT-IR (4000–400 Cm?1), CHN analysis and the structure of the bimetallic compounds also were investigated by the Quantum-chemical modelling. In addition, the samples in nanoparticles mode were studied by thermal analysis (to obtain DTA curves), XRD, FESEM image and EDX analyzing. BET surface analysis was carried out to analyze active surface, pore diameter and porosity of the MxTiyOz nanoparticles. Based on the results, obtained samples as catalysts were able to absorb not just UV but also visible light. Catalysts were able to degrade bromophenol blue as a harmful organic substance under UV and visible lights, although, this ability was more significant when the samples were used under visible light.
关键词： Photocatalysis,1,2 Dihydroxy benzene,Bimetallic complex,Doped titanium,Salicylic acid
更新于2025-09-23 15:22:29
-
The microstructure and optical property of Na-doped ZnO system by sol-gel method
摘要： Pure and Na-doped ZnO (2 at.%, 5 at.% and 10 at.%) films are synthesized by sol-gel method and annealed at 500 °C for 4 h. The as-synthesized nanoparticles are characterized by X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) with energy dispersive X-ray spectroscopy (EDS). The samples exhibited hexagonal ZnO lattice structure and another Na2O2 phase was detected in the 5 at.% Na-doped ZnO sample. The calculated average crystalline size increases from 42.0 nm to 43.5 nm when Na content increased from 0 to 10 at.%. FESEM and TEM analysis identifies that the average size of the Na-doped ZnO nanoparticles lies in between 50 nm and they appear in spheroid-like or rod-like shape. The transmittance of the sample was above 80% and the results of photocatalytic activity show that Na-doped ZnO nanoparticles exhibit higher photodegradation activity (about 91%) than pure ZnO nanoparticles under UV irradiation.
关键词： microstructure,Na-doped,photocatalytic activity.,transparent property,ZnO
更新于2025-09-23 15:22:29
-
ENHANCED STRUCTURAL AND ELECTRICAL PROPERTIES OF LEAD-FREE Y-DOPED (K, Na) NbO3 THIN FILMS
摘要： Yttrium- doped KNN thin films were grown on Si substrates using the sol-gel technique. The profound effects of Yttrium with different content element (mol % = 0, 0.1, 0.3, 0.5, 0.7 and 0.9) on the structural and electrical properties of KNN films were analyzed. The doped samples demonstrated a mainly uniform and homogenous microstructure with grain size less than 100 nm. The existence of Y Kα line shown in EDX spectrum confirmed the presence of Y-dopant in KNN based-compound. Small shift position of the Raman peaks indicated that Y incorporated on the interstitial A-site while broaden FWHM ascribed that Y preferably enters B-site lattice at high dopant concentration. The enhanced electrical resistivity at 0.5 mol % Y suggested that more conduction electrons were formed in KNN lattice structure.
关键词： doped,rare-earth,KNN,thin film,yttrium
更新于2025-09-23 15:22:29