- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Optical Fiber Cladding SPR Sensor Based on Core-Shift Welding Technology
摘要： The typical structure of an optical fiber surface plasmon resonance (SPR) sensor, which has been widely investigated, is to produce the SPR phenomenon by the transmission of light in a fiber core. The traditional method is to peel off the fiber cladding by complex methods such as corrosion, polishing, and grinding. In this paper, the transmitted light of a single-mode fiber is injected into three kinds of fiber cladding by core-shift welding technology to obtain the evanescent field directly between the cladding and the air interface and to build the Kretschmann structure by plating with a 50-nm gold film. The SPR sensing phenomenon is realized in three kinds of fiber cladding of a single-mode fiber, a graded-index multimode fiber, and a step-index multimode fiber. For the step-index multimode fiber cladding SPR sensor, all the light field energy is coupled to the cladding, leading to no light field in the fiber core, the deepest resonance valley, and the narrowest full width at half maximum. The single-mode fiber cladding SPR sensor has the highest sensitivity, and the mean sensitivity of the probe reaches 2538 nm/RIU (refractive index unit) after parameter optimization.
关键词： fiber cladding SPR,surface plasmon resonance
更新于2025-11-28 14:24:03
-
Effects of TiO2 on the performance of silver coated on side-polished optical fiber for alcohol sensing applications
摘要： This work reports the experimental and numerical investigations on the effect of titanium oxide (TiO2) integrated on the optical fiber silver (Ag) surface plasmon resonance (SPR) sensors. In this paper, the numerical simulation is also analyzed using the finite element method (FEM) which shows good agreement. Results are compared with the experimental findings, focusing on the SPR phenomena for refractive index sensing using side-polished optical fiber, where the characteristics of the Ag layer with the integration of TiO2 are optimized. The essential parameters include the thickness of Ag namely 20 nm, 30 nm and 40 nm for optimization studies of SPR properties. TiO2 was then coated on the Ag thin layer to sense isopropanol at different concentration. It is shown that the combination of a 30 nm thickness of Ag layer with a dielectric TiO2 improves sensor performance in terms of sensitivity reading of 268 nm/RIU with a detection limit of 0.012. The main interest is to develop the device with cost effective, ease fabrication and less cumbersome of sensors using TiO2 which one of an alternative material to defeat the oxidation process and avoid charge recombination. If the sensitivity increases at a higher wavelength, it indicates that the TiO2 holds great potential in photonic applications.
关键词： Fiber Optic Alcohol Sensor,Surface plasmon resonance (SPR),Finite element method (FEM)
更新于2025-11-28 14:23:57
-
The effect of the TiO2 film on the performance of the optical fiber SPR sensor
摘要： We studied the effect of the Titanium Oxide (TiO2) film on the performance of the optical fiber SPR with two kinds of probes. The light guiding properties and sensing performance of the D-type optical fiber SPR sensor coated with TiO2 was studied numerically by finite element method (FEM) and the sensing performance of the multimode-single mode-multimode (MSM) hetero-core optical fiber SPR sensor coated with TiO2 was investigated experimentally. The simulation and experimental results for two kinds of probes consistently show that the absence of TiO2 film layer on the gold film can enhance the refractive index sensitivity and tune the resonance curve of the sensor from visible light to near-infrared.
关键词： Hetero-core structure,D-typed structure,Surface plasmon resonance,Finite element method,TiO2 film
更新于2025-11-28 14:23:57
-
A Speckle-Free Angular Interrogation SPR Imaging Sensor Based on Galvanometer Scan and Laser Excitation
摘要： A speckle-free fast angular interrogation surface plasmon resonance imaging (SPRi) sensor based on a diode-pumped all-solid-state laser and galvanometer is reported in this work. A bidirectional scan using a galvanometer realizes the fast scanning of the incidence angle. The experimental results showed that the time needed for completing an SPR dip measurement was decreased to 0.5 s. And through cascading an immovable diffuser and two diffusers rotating in opposite directions, laser speckle was eliminated. The dynamic detection range and the sensitivity reached 4.6 × 10?2 and 1.52 × 10?6 refractive index unit (RIU), respectively, in a 2D array sensor when the angle scanning range was set as 7.5°. More importantly, the results demonstrated that the angular interrogation SPR imaging sensor scheme had the capability to perform fast and high-throughput detection of biomolecular interactions at 2D sensor arrays.
关键词： Speckle-free,Biomolecule interaction,Angular interrogation,Surface plasmon resonance imaging sensor
更新于2025-11-25 10:30:42
-
Surface plasmon resonance of naked gold nanoparticles for photodynamic inactivation of Escherichia coli
摘要： Although antimicrobial photothermal inactivation of naked gold nanostructures using powerful pulsed lasers has been previously studied, there are little reports about their photodynamic antimicrobial properties under the irradiation of low-power density continuous wave lasers. Therefore, this paper attempts to fill this gap. In this paper, we studied the effects of a 40-mW/cm2 continuous Nd:Yag laser at 532 nm and naked gold nanoparticles on inactivation of Escherichia coli ATCC25922. According to our results, 60 min illumination using the Nd:Yag laser caused a 0.15log reduction of the bacterial viability. Also, the employed gold nanoparticles with an average size of 15 nm were toxic to E. coli ATCC 25922 in the concentrations above 0.5 μg/ml. In addition, synergistic effects of 0.5 μg/ml gold nanoparticles and the light illumination led to a 2.43log reduction of the viability after a 60-min exposure and did not show any considerable temperature change on the media. The obtained results were justified based on the possible interaction mechanisms of low-power density laser lights and naked gold nanoparticles. The paper is proposed as a prelude for future research about localized inactivation of resistant pathogens with minimum side effects on neighbor tissues.
关键词： Photodynamic inactivation,Gold nanoparticles,Low-power density laser,Surface plasmon resonance
更新于2025-11-25 10:30:42
-
Monolithic metal dimer-on-film structure: new plasmonic properties introduced by the underlying metal
摘要： Dimers -two closely-spaced metallic nanostructures- are one of the primary nanoscale geometries in plasmonics, supporting high local field enhancements in their interparticle junction under excitation of their hybridized “bonding” plasmon. However, when a dimer is fabricated on a metallic substrate, its characteristics are changed profoundly. Here we examine the properties of an Au dimer on an Au substrate. This structure supports a bright “bonding” dimer plasmon, screened by the metal, and a lower energy magnetic charge transfer plasmon. Changing the dielectric environment of the dimer-on-film structure reveals a broad family of higher-order hybrid plasmons in the visible region of the spectrum. Both the localized surface plasmons resonances (LSPR) of the individual dimer-on-film structures as well as their collective surface lattice resonances (SLR) show a highly sensitive refractive index sensing response. Implementation of such all-metal magnetic-resonant nanostructures offers a promising route to achieve higher-performance LSPR- and SLR-based plasmonic sensors.
关键词： Plasmonics,localized surface plasmon resonance,surface lattice resonance,LSPR sensing,refractive index sensing
更新于2025-11-21 11:24:58
-
Dielectrophoretic cell trapping for improved surface plasmon resonance imaging sensing
摘要： The performance of conventional surface plasmon resonance (SPR) biosensors can be limited by the diffusion of the target analyte to the sensor surface. This work presents an SPR biosensor that incorporates an active mass-transport mechanism based on dielectrophoresis (DEP) and electroosmotic flow to enhance analyte transport to the sensor surface and reduce the time required for detection. Both these phenomena rely on the generation of AC electric fields that can be tailored by shaping the electrodes that also serve as the SPR sensing areas. Numerical simulations of electric field distribution and microparticle trajectories were performed to choose an optimal electrode design. The proposed design improves on previous work combining SPR with DEP by using face-to-face electrodes, rather than a planar interdigitated design. Two different top-bottom electrode designs were experimentally tested to concentrate firstly latex beads and secondly biological cells onto the SPR sensing area. SPR measurements were then performed by varying the target concentrations. The electrohydrodynamic flow enabled efficient concentration of small objects (3 μm beads, yeasts) onto the SPR sensing area, which resulted in an order of magnitude increased SPR response. Negative dielectrophoresis was also used to concentrate HEK293 cells onto the metal electrodes surrounded by insulating areas, where the SPR response was improved by one order of magnitude.
关键词： dielectrophoresis,electro-osmosis,biosensing instrumentation,top-bottom electrodes,surface plasmon resonance
更新于2025-11-21 11:24:58
-
A RAGE-Targeted Antibody-Drug Conjugate: Surface Plasmon Resonance as a Platform for Accelerating Effective ADC Design and Development
摘要： Antibodies, antibody-like molecules, and therapeutics incorporating antibodies as a targeting moiety, such as antibody-drug conjugates, offer significant potential for the development of highly efficacious drugs against a wide range of disorders. Despite some success, truly harnessing the superior targeting properties of these molecules requires a platform from which to effectively identify the best candidates for drug development. To streamline the development of antibody-drug conjugates targeting gynecological cancers within our laboratory, we incorporated surface plasmon resonance analysis (Biacore? T200) into our development toolkit. Antibodies, selected based on positive ELISA screens as suitable for development as antibody-drug conjugates, were evaluated using surface plasmon resonance to determine a wide range of characteristics including specificity, kinetics/affinity, the effect of linker binding, the impact of the drug to antibody ratio, and the effect of endosomal pH on antibody-antigen binding. Analysis revealed important kinetics data and information regarding the effect of conjugation and endosomal pH on our antibody candidates that correlated with cell toxicity and antibody internalization data. As well as explaining observations from cell-based assays regarding antibody-drug conjugate efficacies, these data also provide important information regarding intelligent antibody selection and antibody-drug conjugate design. This study demonstrates the application of surface plasmon resonance technology as a platform, where detailed information can be obtained, supporting the requirements for rapid and high-throughput screening that will enable enhanced antibody-drug conjugate development.
关键词： antibodies,antibody-drug conjugates,gynecological cancers,binding kinetics,surface plasmon resonance
更新于2025-11-21 11:08:12
-
Molecularly imprinted based surface plasmon resonance nanosensors for microalbumin detection
摘要： Human serum albumin (HSA) is a major blood plasma protein also found in urine where its existence may be a marker of some types of liver or kidney dysfunction. Herein, we fabricated a novel surface plasmon resonance (SPR) nanosensor for selective, sensitive, and label-free microalbumin detection both in aqueous and urine sample solutions. Firstly, HSA-imprinted nanoparticles were synthesized, which consist of ethylene glycol dimethacrylate and N-methacryloyl-L-leucine as a cross-linker and functional monomer. The nanoparticles were characterized by zeta-size and scanning electron microscope analyses and were dropped onto the SPR chip surface to make HSA sensitive nanosensor. Characterization studies of HSA-imprinted SPR chip were carried out by atomic force microscopy, Fourier-transform infrared spectroscopy, contact angle, and ellipsometer. The limit of detection and limit of quantification values of HSA-imprinted SPR nanosensor were calculated as 0.7 pM and 1.9 pM for the concentration range of 0.15-500 nM. Selectivity studies of HSA-imprinted SPR nanosensor were achieved with hemoglobin and transferrin proteins which were chosen as competitor molecules. HSA-imprinted SPR nanosensor was displayed highly selective and sensitive to HSA.
关键词： surface plasmon resonance,nanosensor,nanoparticles,microalbumin detection
更新于2025-11-21 11:03:13
-
Cu nanoclusters in ion exchanged soda-lime glass: Study of SPR and nonlinear optical behavior for photonics
摘要： Nanomaterials with large optical nonlinearities have received considerable attention in the field of modern science and nanotechnology. In this paper, we have studied nonlinear optical and surface plasmon resonance properties and behavior of Cu nanoclusters formed in ion exchanged soda-lime glass. The soda-lime glasses were successfully doped with Cu nanoclusters in the ion-exchange process. The size of the clusters estimated from the optical absorption spectroscopy results closely matched with those obtained from the transmission electron microscopy data. The results revealed that spherical shaped Cu nanoclusters were homogeneously distributed in the glass matrix and the size of the Cu nanoclusters varied from 4 to 10 nm. The structure and chemical state were further analyzed by X-ray diffraction and X-ray photoelectron spectroscopy. The nonlinear optical behavior of the materials was analyzed using femtosecond Z-scan technique. The nonlinear refraction index (n2), nonlinear absorption coefficient (β) and the third-order nonlinear optical susceptibility (χ(3)) were estimated to be -1.72 × 10?17 m2/W, 9.96 × 10?11 m/W, and 0.56 × 10?11 esu, respectively, which shows possible application in the field of photonics.
关键词： Surface plasmon resonance,Z-scan technique,Metal forming and shaping,Structural,Nanoparticles
更新于2025-11-20 15:33:11