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- 摘要
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- 实验方案
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Real-time profiling Anti-EpCAM Based Immune capture, from Molecules to Cells using MP-SPR
摘要： Antibodies of epithelial cell-adhesion-molecule (anti-EpCAM)-based interfaces have proven to be highly efficient at capturing circulating tumor cells (CTCs). To achieve the bonding of anti-EpCAM to the interface, biotin and streptavidin are used to modify the surface. These processes are critical to subsequent cell-capture efficiencies. However, quantitative research on the interactions between biotin, streptavidin and biotinylated anti-EpCAM on the interface is lacking. In this work, the thermodynamics and kinetics of biomolecular interactions were determined by using surface plasmon resonance. The equilibrium binding affinities for biotinylated anti-EpCAM to streptavidin and streptavidin to biotin (illustrated by biotin-PEG400-thiol) were found to be 2.75×10^6 M^-1 and 8.82×10^6 M^-1, respectively. Each streptavidin can bind up to 2.30 biotinylated anti-EpCAM under thermodynamic equilibrium. The findings provide useful information to optimize the modification of anti-EpCAM and improve the capture efficiency of CTCs.
关键词： surface plasmon resonance,antibodies of epithelial cell-adhesion-molecule,cell capture,biotin–streptavidin interaction,thermodynamics,kinetics
更新于2025-09-23 15:23:52
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Theoretical demonstration of Single polarization single mode hollow core anti-resonance fiber using surface plasmon resonance
摘要： We designed a hollow core anti-resonance fiber based on surface plasmon resonance and optimized its characteristics by using the finite element method with perfectly matched layer boundary condition. A single mode single polarization bandwidth, up to 200 nm, is obtained by employing surface plasmon resonance which is produced by two embedded gold wires. Only the x-polarized fundamental mode of the fiber suffers a high loss because of the surface plasmon resonance. In addition, single mode guidance is obtained by adjusting the size of cladding tubes. Simulation results show that the designed fiber has an effective single polarization single mode guidance in the wavelength range from 1.3 to 1.5μm. In this range, both the higher order mode extinction ratio and the polarization mode extinction ratio are more than 100. The structure is shown to have a good fabrication tolerance with respect to variations in the position and size of the gold wires. The proposed fiber has many potential applications in polarization splitters, fiber-optic gyroscopes and polarization-dependent fiber systems.
关键词： Anti-resonance hollow core fiber,Surface plasmon resonance,Single polarization single mode.
更新于2025-09-23 15:23:52
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Ruler equation for precisely tailoring the resonance frequency of terahertz U-shaped metamaterials
摘要： Artificially controlling the spectral response of metamaterials is important for the applications of functional devices. Here, we identify a simple ruler equation for describing the direct relation between the resonance frequencies and geometric parameters in terahertz U-shaped metamaterials. Utilizing this ruler equation, we demonstrate the switching of the multi-band resonator which can be customized to work at expectant frequency bands. This ruler equation provides a practical guidance on tailoring the resonance frequency and paves the way for the development of metamaterial-based terahertz functional devices.
关键词： terahertz,surface plasmon,metamaterials
更新于2025-09-23 15:23:52
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Haloalkanes and aromatic hydrocarbons sensing using Langmuir–Blodgett thin film of pillar[5]arene-biphenylcarboxylic acid
摘要： Here, a pillar[5]arene derivative including biphenylcarboxylic acid groups was designed for obtaining a macrocycle with an ideal cavity for volatile organic compounds. The pillar[5]arene-biphenylcarboxylic acid (P5-BPCA) based Langmuir-Blodgett (LB) thin films were produced onto 50 nm thick gold-coated glass and 3.5 MHz quartz crystal substrates to form a thin film chemical sensor element. Surface plasmon resonance (SPR) and Quartz crystal microbalance (QCM) techniques were employed to characterize all the P5-BPCA LB thin film layers. The mass of LB film layer loaded onto a quartz crystal and the resonance frequency shifts per layer were determined to be 711.71 ng per layer (2.68 ng mm?2) and 48.24 Hz per layer, respectively. The P5-BPCA LB thin film sensor element was exposed to various haloalkane and aromatic hydrocarbon vapors. The sensitivities of the P5-BPCA LB film sensor were determined between 1.776 and 3.976 Hz ppm-1. Sensitivity with detection limits were obtained between 0.754 and 1.689 ppm against organic vapors. The results showed that P5-BPCA LB thin film was highly selective with a large response to chloromethane vapor.
关键词： Quartz Crystal Microbalance,Pillararene,Langmuir-Blodgett,Volatile Organic Compounds,Swelling,Surface Plasmon Resonance
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - Chengdu (2018.3.26-2018.3.28)] 2018 IEEE International Conference on Computational Electromagnetics (ICCEM) - Beam-Scanning Antenna Excited by Planar Spoof Surface Plasmon Polaritons
摘要： a wide-angle frequency-controlled beam-scanning antenna excited by planar spoof surface plasmon polaritons (SPPs) is proposed in this paper. The scanning angle and the gains of the proposed antenna can reach 83 degrees and 11.5dBi, respectively. The features of high gain, planar structure and wide scanning angle make this kind of antennas have great values in integrated communication systems.
关键词： antenna,beam-scanning,spoof surface plasmon polaritons (SPPs)
更新于2025-09-23 15:23:52
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Direct Imaging of Surface Plasmon-Driven Hot Electron Flux on the Au Nanoprism/TiO <sub/>2</sub>
摘要： Direct measurement of hot electron flux from a plasmonic Schottky nanodiode is important for obtaining fundamental insights explaining the mechanism for electronic excitation on a surface. Here, we report the measurement of photo-induced hot electrons on a triangular Au nanoprism on TiO2 under incident light with photoconductive atomic force microscopy (pc-AFM), which is direct proof of the intrinsic relation between hot electrons and localized surface plasmon resonance. We find that the local photocurrent measured on the boundary of the Au nanoprism is higher than that inside the Au nanoprism, indicating that field confinement at the boundary of the Au nanoprism acts as a hot spot, leading to the enhancement of hot electron flow at the boundary. Under incident illumination with a wavelength near the absorption peak (645 nm) of a single Au nanoprism, localized surface plasmon resonance resulted in the generation of a higher photo-induced hot electron flow for the Au nanoprism/TiO2, compared with that at a wavelength of 532 nm. We show that the application of a reverse bias results in a higher photocurrent for the Au nanoprism/TiO2, which is associated with a lowering of the Schottky barrier height caused by the image force. These nanoscale measurements of hot electron flux with pc-AFM indicate efficient photon energy transfer mediated by surface plasmons in hot electron-based energy conversion.
关键词： hot electron,Photoconductive atomic force microscopy,localized surface plasmon resonance,Schottky diode,field confinement,Au nanoprism
更新于2025-09-23 15:23:52
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Rejection of Spoof SPPs Using the Second Resonant Mode of Vertical Split-Ring Resonator
摘要： In this letter, the studies of the vertical split-ring resonator (VSRR) at its second resonant mode are carried out for the first time. The VSRR can be regarded as an electric resonator at such resonant mode, which is proven by its resonant current distribution. Then, a new type of rejection plasmonic filter is constructed by adding the VSRR on the planar spoof surface plasmon polariton (SPP) waveguide using double-side corrugated metallic strips. The second resonance of the VSRR is excited by the z-component of the electric field of the spoof SPP mode, near which the SPP propagation is prevented. Utilizing this principle, a plasmonic filter with broadband rejection is designed and fabricated. The measurement result is presented to confirm the highly efficient filtering performance of the proposed filter, which makes it possible to be applied in the advanced integrated plasmonic devices and circuits at microwave and terahertz frequencies.
关键词： vertical split-ring resonator (VSRR),Rejection plasmonic filter,spoof surface plasmon polaritons (SPPs)
更新于2025-09-23 15:22:29
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Reflective SPR Sensor for Simultaneous Measurement of Nitrate Concentration and Temperature
摘要： In this paper, a reflective fiber optic sensor based on surface plasmon resonance (SPR) was proposed to measure nitrate concentration and temperature simultaneously. The sensor adopted reflective structure, and used gold film as metal film for exciting SPR. Then, Cu-nanoparticles/carbon nanotubes composite film was used as sensitive material to measure nitrate concentration, and it was coated on the surface of the gold film by the dip coating method. Finally, polydimethylsiloxane was coated on part of the sensing probe to produce two independent resonance dips in the output spectrum. When the nitrate concentration and temperature changed, the two resonance dips would all move, but with different sensitivities. By monitoring the wavelength shifts of the two dips, the nitrate concentration and temperature could be measured simultaneously with using the dual-wavelength matrix method. Experimental results demonstrated that the measurement sensitivity of the nitrate concentration could reach 3.25 nm/lg[M], and the temperature measurement sensitivity was ?2.02 nm/°C. Moreover, the sensor had high-mechanical strength and was easy to package, which could be applied to remote measurement field.
关键词： reflective surface plasmon resonance (SPR),optical fiber sensor,Nitrate concentration,simultaneous measurement,temperature
更新于2025-09-23 15:22:29
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Investigation of a low cost tapered plastic fiber optic biosensor based on manipulation of colloidal gold nanoparticles
摘要： We demonstrate a low cost Tapered Fiber Optic Biosensor (TFOBS) based on manipulation of colloidal gold nanoparticle in the evanescent field of tapered fiber. The sensor consists of a biconical tapered plastic optical fiber with colloidal gold nanoparticles coated on the tapered region. The strength of evanescent field absorption as a function of gold nanoparticle size is evaluated using Finite Difference Time Domain simulation. Simulation results suggest that in order to achieve maximum absorption in visible range of wavelength, the size of the gold nanoparticle should be in the range 3-4 nm. Gold nanoparticle of desired size is then synthesized and coated on the tapered region to fabricate a TFOBS. It is found experimentally that coating of gold nanoparticles enhances the fraction of light coming out to the cladding surface. This is explained as a consequence of local surface plasmonic resonance. The TFOBS is then tested for its sensing application to detect Bovine Serum Albumin. Level of detection of the proposed sensor is calculated and is found as 0.326gm/dL.As normal albumin level in healthy human blood serum is between 3.5 to 5.5gm/dL, the proposed TFOBS can be used as a low cost accurate albumin sensor.
关键词： Tapered Fiber Optic Sensor,Local Surface Plasmon Resonance,Manipulation of nanoparticle
更新于2025-09-23 15:22:29
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Novel SPR sensing platform based on superstructure MoS2 nanosheets for ultrasensitive detection of mercury ion
摘要： Water contamination by Hg2+ and its detection have attracted much attention. However, the detection limit for Hg2+ by traditional techniques is 200 pM, which is far higher than the maximum Hg2+ concentration allowed in effluent (7.5 pM). Here, we developed a novel surface-plasmon-resonance (SPR) sensor for Hg2+ detection by using superstructure MoS2 nanosheets as the sensing layer material. The simulations and structural characterizations reveal that the ultra-high sensitivity of the SPR sensor arises from the large interlayer spacing and sufficient unsaturated bonds in MoS2 superstructure, which promotes transporting and adsorbing Hg2+. Surprisingly, the Hg2+ detection limit of the SPR sensor is as low as 1.0 pM, which is 200 times lower than those of existing Hg2+ sensors. Therefore, our research presents an effective method for detecting ultra-low concentration of Hg2+ and also reveals the sensing mechanism of MoS2 – based SPR sensor. This not only extends the application of superstructure MoS2 nanosheets, but also provides a novel design idea for the development of ultra-sensitive detection technologies.
关键词： surface plasmon resonance,biosensor,superstructure,MoS2,mercury
更新于2025-09-23 15:22:29