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- 摘要
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- 实验方案
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Photo-thermal Synergistically Catalytic Conversion of Glycerol and Carbon Dioxide to Glycerol Carbonate over Au/ZnWO4-ZnO Catalysts
摘要： Converting glycerol and CO2 into glycerol carbonate offers a green pathway for utilizing biodiesel by-product glycerol and greenhouse gas CO2 as well as synthesizing the important chemical compound glycerol carbonate. In this study, for the first time, the abundant visible light was introduced into thermal-driven glycerol carbonylation system, aiming to improve catalyst performance via breaking the thermodynamic equilibrium limitations. Here x%Au/ZnWO4-ZnO catalysts were designed for the photo-thermal catalytic system. It was found that, ZnWO4-ZnO itself was effective in glycerol carbonylation even under thermal-driven condition, and the loading of plasmonic Au further enhanced the catalytic performances especially with visible light irradiation. The visible light responsivity of the catalysts and reaction temperatures played important roles for the photo-thermal performance of x%Au/ZnWO4-ZnO, indicating the strong photo-thermal synergistic effect for the highly promoted catalytic performance. This study suggests the photo-thermal synergistic catalysis is one of efficient approaches for further improving catalytic performance.
关键词： photo-thermal,glycerol carbonylation,localized surface plasmon resonance,synergistic effect,glycerol carbonate synthesis
更新于2025-09-09 09:28:46
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Tunable triple-band graphene refractive index sensor with good angle-polarization tolerance
摘要： In this article, we design a triple-band graphene refractive index sensor with good angle-polarization tolerance, which is composed of graphene elliptic-circular nanodisk resonators periodically arranged on a dielectric substrate. The numerical results indicate that the resonant wavelengths of three modes of graphene resonators show consecutively linear tunability when the refractive index of the surrounding medium varies, and the sensitivity is up to 11.56 μm/RIU. The sensing range can be further adjusted by controlling the doping level of graphene. In addition, the proposed graphene sensor maintains polarization insensitivity over a wide angular range (0-60°), showing very good angle-polarization tolerance. This work enables us to achieve a tunable triple-band sensor and provides potential value for label-free biomedical sensing.
关键词： graphene,surface plasmon resonance,refractive index sensor,metamaterials
更新于2025-09-09 09:28:46
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Fluorescent Metal-Semiconductor Hybrid Structures by Ultrasound-Assisted In-Situ Growth of Gold Nanoparticles on Silica-Coated CdSe-Dot/CdS-Rod Nanocrystals
摘要： Gold nanocrystals (AuNCs) were grown on the surface of silica coated CdSe-dot/CdS-rod core/shell nanocrystals by reduction of Au3+ ions in polyethylene glycol under ultrasonic irradiation. The polyethylene glycol not only prevents the penetration of gold ions or precursor molecules into the silica shell, but it also acts as the reducing agent for Au3+ ions. The silica shell’s surface promotes the heterogeneous nucleation of gold nanocrystals, while the ultrasonic irradiation accelerates and enhances the gold nucleation on the silica surface, and ensures the formation of AuNCs with a relatively narrow size distribution. The plasmon-exciton interaction in these metal-semiconductor hybrid systems leads to decreased fluorescence lifetimes and strongly reduced fluorescence blinking of individual hybrid structures.
关键词： ultrasonic irradiation,Gold nanocrystals,CdSe-dot/CdS-rod nanocrystals,plasmon-exciton interaction,polyethylene glycol
更新于2025-09-09 09:28:46
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Development of a surface plasmon resonance immunosensor and ELISA for 3-nitrotyrosine in human urine
摘要： 3-Nitrotyrosine (3-NT) is thought to be a relevant biomarker of nitrosative stress which is associated with many inflammatory and chronic diseases. It is necessary to develop confidential method for specific and sensitive 3-NT detection. In this paper, on the basis of anti-3-NT specific antibody, we developed a label-free indirect competitive surface plasmon resonance (SPR) immunosensor and ELISA for the detection of 3-NT. Under the optimized conditions, the SPR immunosensor can obtain a linear range of 0.17–6.07 μg/mL and a limit of detection (LOD) of 0.12 μg/mL while the ELISA can reach 0.33–9.94 μg/mL and a LOD of 0.24 μg/mL.The selectivity of 3-NT was also testified by six kinds of amino acid analogues. Besides, the developed SPR immunosensor was compared thoroughly with a conventional ELISA in spiked analysis of urine samples. Good recoveries and correlation between these two methods were observed (R2 = 0.964). Therefore, it is concluded that the automated SPR platform can be applied to quantify 3-NT in biological samples with its sensitivity, accuracy, and real-timing.
关键词： ELISA,Human urine,3-nitrotyrosine,Surface plasmon resonance (SPR)
更新于2025-09-09 09:28:46
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The photonic candle
摘要： Using light to manipulate small particles has proven an indispensable tool for ‘tweezing’, sorting and force measurements. To achieve effective optical traps with high ‘stiffness’, researchers often go to great lengths to tailor light fields, for example by using holographic elements. Now, Aliaksandra Ivinskaya and colleagues from Russia, the USA, the UK and Israel predict that small particles can be manipulated using a plane wave of light and a simple flat surface of an anisotropic media supporting hyperbolic modes. Their hyperbolic metamaterial is composed of metal and dielectric layers and is potentially less affected by losses and offers more broadband capability than purely plasmonic approaches. In their theoretical study a small dielectric sphere near a hyperbolic metamaterial is considered. The particle is sufficiently small to provide the required momentum to excite both surface plasmon and bulk hyperbolic waves from incident plane waves. Strong optical pulling forces were predicted over the 400–800 nm wavelength range thanks to the broadband high density of states of hyperbolic modes.
关键词： hyperbolic modes,nano-optics,optical manipulation,metasurface,plasmon
更新于2025-09-09 09:28:46
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Ultrawide tunability
摘要： Using light to manipulate small particles has proven an indispensable tool for ‘tweezing’, sorting and force measurements. To achieve effective optical traps with high ‘stiffness’, researchers often go to great lengths to tailor light fields, for example by using holographic elements. Now, Aliaksandra Ivinskaya and colleagues from Russia, the USA, the UK and Israel predict that small particles can be manipulated using a plane wave of light and a simple flat surface of an anisotropic media supporting hyperbolic modes. Their hyperbolic metamaterial is composed of metal and dielectric layers and is potentially less affected by losses and offers more broadband capability than purely plasmonic approaches. In their theoretical study a small dielectric sphere near a hyperbolic metamaterial is considered. The particle is sufficiently small to provide the required momentum to excite both surface plasmon and bulk hyperbolic waves from incident plane waves. Strong optical pulling forces were predicted over the 400–800 nm wavelength range thanks to the broadband high density of states of hyperbolic modes.
关键词： hyperbolic modes,nano-optics,optical manipulation,metasurface,plasmon
更新于2025-09-09 09:28:46
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Compact and efficient
摘要： Using light to manipulate small particles has proven an indispensable tool for ‘tweezing’, sorting and force measurements. To achieve effective optical traps with high ‘stiffness’, researchers often go to great lengths to tailor light fields, for example by using holographic elements. Now, Aliaksandra Ivinskaya and colleagues from Russia, the USA, the UK and Israel predict that small particles can be manipulated using a plane wave of light and a simple flat surface of an anisotropic media supporting hyperbolic modes. Their hyperbolic metamaterial is composed of metal and dielectric layers and is potentially less affected by losses and offers more broadband capability than purely plasmonic approaches. In their theoretical study a small dielectric sphere near a hyperbolic metamaterial is considered. The particle is sufficiently small to provide the required momentum to excite both surface plasmon and bulk hyperbolic waves from incident plane waves. Strong optical pulling forces were predicted over the 400–800 nm wavelength range thanks to the broadband high density of states of hyperbolic modes.
关键词： hyperbolic modes,nano-optics,optical manipulation,metasurface,plasmon
更新于2025-09-09 09:28:46
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Anomalous K-Point Phonons in Noble Metal/Graphene Heterostructure Activated by Localized Surface Plasmon Resonance
摘要： Metal/graphene interface has been one of the most important research topics with regard to charge screening, charge transfer, contact resistance, and solar cells. Chemical bond formation of metal/graphene can be deduced from the defect induced D-band and its second-order mode, 2D band, measured by Raman spectroscopy, as a simple and non-destructive method. However, a phonon mode located at ~ 1350 cm-1, which is normally known as the defect-induced D-band, is intriguing for graphene deposited with noble metals (Ag, Au, and Cu). We observe anomalous K-point phonons in non-reactive noble metal/graphene heterostructure. The intensity ratio of the mid-frequency mode at ~ 1350 cm-1 over G-band (~1590 cm-1) exhibits non-linear but resonant behavior with the excitation laser wavelength and more importantly, the phonon frequency–laser energy dispersion is ~ 10-17 cm-1/eV, which is much less than the conventional range. These phonon modes of graphene at non-zero phonon wave vector (q ≠ 0) around K points are activated by localized surface plasmon resonance, and not by the defects due to chemical bond formation of metal/graphene. This hypothesis is supported by density function theory (DFT) calculations for noble metals and Cr along with the measured contact resistances.
关键词： K-point phonon,Raman,graphene,localized surface plasmon,noble metal
更新于2025-09-09 09:28:46
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Child-Langmuir law for photoinjectors
摘要： The space-charge ?eld at the cathode limits the current density extracted from particle sources such as photoinjectors. For a long time, the maximum current has been estimated by using the classical Child-Langmuir law, which is derived with an assumption inconsistent with the conditions of modern laser-driven electron guns. Here, we introduce a theoretical model that accurately accounts for space-charge effects in transversely con?ned particle beams emerging from photocathodes. The model enables us to (i) determine the maximum current density extractable from the photocathode for an arbitrary cathode radius, (ii) reveal its dependence on the transverse pro?le of the particle beam, and (iii) predict its upper limit for structured beams such as the ones produced by surface-plasmon resonance-enhanced photocathodes.
关键词： photocathodes,space-charge effects,Child-Langmuir law,photoinjectors,surface-plasmon resonance
更新于2025-09-09 09:28:46
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High-sensitivity refractive index sensor with tunable detection range based on dual-core resonance effect in gold-coated photonic crystal fibers
摘要： A high-sensitivity refractive index (RI) sensor with wide tunable detection range based on the dual-core resonance of photonic crystal fibers are presented and studied by the finite element method. A cladding air hole coated with gold film is designed as the microfluidic channel for surface plasmon resonance sensing. The channel filled with liquid analyte acts as a defective core. The directional energy coupling between the fiber core and the defective core which determines the sensing performance is greatly influenced by both the RI of the filled liquid and the structural parameters. Numerical results show that the sensitivity of the sensor increases with the increase of the diameter of the analyte channel, and the RI detection range decreases with the increase of this diameter. So we tune the detection range by adjusting the diameter of the analyte channel to meet specific measurement requirements. As the diameter increases from 1.5 μm to 2.4 μm, the detection range shrinks from 1.45–1.62 to 1.45–1.48, both with the high spectral sensitivity 10 392 nm/RIU and 25 040 nm/RIU, respectively. The sensor with wide adjustable detection range shows great advantages in the field of biochemical, chemistry and environmental detection.
关键词： refractive index sensor,photonic crystal fiber,wide detection range,surface plasmon resonance,high-sensitivity
更新于2025-09-09 09:28:46