- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Polymer Optical Fibers for Sensing
摘要： Sensing techniques based on optical ?bers are used in numerous key ?elds. For example, optical ?ber sensors are exploited in medical diagnostics, environmental monitoring, physical parameters detection, industrial applications, food safety, and security. In fact, optical ?ber sensors are used for their numerous capabilities, as for example when in the detection fast, portable, low-cost, small size, and/or rugged sensor systems are needed. In general, the optical ?ber for sensing applications can be a glass one, a specialty one, or a polymer one. Polymer optical ?bers (POFs) are especially advantageous due to their excellent ?exibility, easy manipulation, large diameter, resilience, and the fact that plastic is able to withstand smaller bend radii than glass. These POF sensors, intrinsic and extrinsic, combined with di?erent kinds of receptors can be directly connected to an online platform by interface software, allowing storing, analyzing, and displaying the sensor’s data, to realize low-cost biochemical sensors for several applications. In this work, two plasmonic POF sensors, one intrinsic and another one extrinsic, that can be used in biochemical applications are described.
关键词： optical sensors,intrinsic and extrinsic optical ?ber sensors,polymer optical ?bers,plasmonic sensors,biosensors
更新于2025-09-23 15:19:57
-
Au@Ag Corea??Shell Nanorods Support Plasmonic Fano Resonances
摘要： In this work, we investigated experimentally and theoretically the plasmonic Fano resonances (FRs) exhibited by core–shell nanorods composed of a gold core and a silver shell (Au@Ag NRs). The colloidal synthesis of these Au@Ag NRs produces nanostructures with rich plasmonic features, of which two different FRs are particularly interesting. The FR with spectral location at higher energies (3.7 eV) originates from the interaction between a plasmonic mode of the nanoparticle and the interband transitions of Au. In contrast, the tunable FR at lower energies (2.92–2.75 eV) is ascribed to the interaction between the dominant transversal LSPR mode of the Ag shell and the transversal plasmon mode of the Au@Ag nanostructure. The unique symmetrical morphology and FRs of these Au@Ag NRs make them promising candidates for plasmonic sensors and metamaterials components.
关键词： Au@Ag NRs,metamaterials,core–shell nanorods,plasmonic Fano resonances,plasmonic sensors
更新于2025-09-19 17:13:59
-
Influence of Design Parameters on Multilayered Nanoplasmonic Structures in Modified Kretschmann-Raether Configurations
摘要： Surface Plasmon Resonance (SPR) technique has been of recent interest in many fields such as biological and chemical sensing, defense-related applications, etc. The introduction of graphene sheet (metal-like optical properties) over a thin-film layers plays a significant role in generating SPR. Different nanoplasmonic structures like Coupled Waveguide SPR (CWSPR) and Long Range SPR (LRSPR) are considered with modified Kretschmann-Raether configurations for different wavelengths in visible range for plasmonic sensors application. Characteristic Transfer Matrix (CTM) method in MATLAB environment is employed to obtain the theoretical results of LRSPR-based nanoplasmonic structures. Based on different compositions, minimum reflectivity as obtained is reported here. Due to the incorporation of additional graphene thin layer, keeping the angle of incidence constant, the percentage of reflectivity is being increased significantly, thereby reducing the transmission within the layers. With the variation of thickness, refractive index of different layers as well as wavelength of the LASER source, one may optimize the structures to obtain best possible performance.
关键词： Plasmonics,Surface Plasmon Resonance,LRSPR,Plasmonic Sensors,Sensitivity,CWSPR,Kretschmann-Raether Configuration,Figure of Merit
更新于2025-09-19 17:13:59
-
SERS-based molecularly imprinted plasmonic sensor for highly sensitive PAH detection
摘要： A novel hybrid plasmonic platform based on the synergetic combination of a molecularly imprinted polymer (MIP) thin film with Au nanoparticles (NPs) assemblies, noted as Au@MIP, was developed for surface-enhanced Raman scattering (SERS) spectroscopy recognition of polycyclic aromatic hydrocarbons (PAHs). While the MIP trapped the PAH close to the Au surface, the plasmonic NPs enhanced the molecule Raman signal. The Au@MIP fabrication comprises a two-step procedure, first, the layer-by-layer deposition of Au NPs on glass and their further coating with a uniform MIP thin film. Profilometry analysis demonstrated that the thickness and homogeneity of the MIP film could be finely tailored by tuning different parameters such as prepolymerization time or spin-coating rate. Two different PAH molecules, pyrene or fluoranthene, were used as templates for the fabrication of pyrene- or fluoranthene-based Au@MIP substrates. The use of pyrene or fluoranthene, as a template molecule to fabricate the Au@MIP thin films, enabled its ultradetection in the nM regime with a 100-fold improvement compared with the non-imprinted plasmonic sensors (Au@NIPs). The SERS data analysis allows to estimate the binding constant of the template molecule to the MIP. The selectivity of both pyrene- and fluoranthene-based Au@MIPs was analyzed against three PAHs of different sizes. The results displayed the important role of the template molecule used for the Au@MIPs fabrication in the selectivity of the system. Finally, the practical applicability of pyrene-based Au@MIPs is shown by performing the detection of pyrene in two real samples: creek water and seawater. The design and optimization of this type of plasmonic platform pave the way for the detection of other relevant (bio)molecules in a broad range of fields such as environmental control, food safety or biomedicine.
关键词： Molecularly imprinted polymers,plasmonic sensors,polycyclic aromatic hydrocarbons,SERS,hybrid nanostructures,environmental analysis
更新于2025-09-19 17:13:59
-
Interfacial Capillarya??Forcea??Driven Selfa??Assembly of Monolayer Colloidal Crystals for Supersensitive Plasmonic Sensors
摘要： Colloidal lithography technology based on monolayer colloidal crystals (MCCs) is considered as an outstanding candidate for fabricating large-area patterned functional nanostructures and devices. Although many efforts have been devoted to achieve various novel applicatons, the quality of MCCs, a key factor for the controllability and reproducibility of the patterned nanostructures, is often overlooked. In this work, an interfacial capillary-force-driven self-assembly strategy (ICFDS) is designed to realize a high-quality and highly-ordered hexagonal monolayer MCCs array by resorting the capillary effect of the interfacial water film at substrate surface as well as controlling the zeta potential of the polystyrene particles. Compared with the conventional self-assembly method, this approach can realize the reself-assembly process on the substrate surface with few colloidal aggregates, vacancy, and crystal boundary defects. Furthermore, various typical large-scale nanostructure arrays are achieved by combining reactive ion etching, metal-assisted chemical etching, and so forth. Specifically, benefiting from the as-fabricated high-quality 2D hexagonal colloidal crystals, the surface plasmon resonance (SPR) sensors achieve an excellent refractive index sensitivity value of 3497 nm RIU?1, which is competent for detecting bovine serum albumin with an ultralow concentration of 10?8 m. This work opens a window to prepare high-quality MCCs for more potential applications.
关键词： colloidal lithography,plasmonic sensors,monoloidal colloidal self-assembly,nanostructure arrays,interfacial capillary force
更新于2025-09-16 10:30:52
-
Bifunctionalized Silver Nanoparticles as Hg2+ Plasmonic Sensor in Water: Synthesis, Characterizations, and Ecosafety
摘要： In this work, hydrophilic silver nanoparticles (AgNPs), bifunctionalized with citrate (Cit) and L-cysteine (L-cys), were synthesized. The typical local surface plasmon resonance (LSPR) at λ max = 400 nm together with Dynamic Light Scattering (DLS) measurements (<2RH = 8 ± 1 nm) and TEM studies (? = 5 ± 2 nm) confirmed the system nanodimension and the stability in water. Molecular and electronic structures of AgNPs were investigated by FTIR, SR-XPS, and NEXAFS techniques. We tested the system as plasmonic sensor in water with 16 different metal ions, finding sensitivity to Hg2+ in the range 1–10 ppm. After this first screening, the molecular and electronic structure of the AgNPs-Hg2+ conjugated system was deeply investigated by SR-XPS. Moreover, in view of AgNPs application as sensors in real water systems, environmental safety assessment (ecosafety) was performed by using standardized ecotoxicity bioassay as algal growth inhibition tests (OECD 201, ISO 10253:2006), coupled with determination of Ag+ release from the nanoparticles in fresh and marine aqueous exposure media, by means of ICP-MS. These latest studies confirmed low toxicity and low Ag+ release. Therefore, these ecosafe AgNPs demonstrate a great potential in selective detection of environmental Hg2+, which may attract a great interest for several biological research fields.
关键词： silver nanoparticles,heavy metal sensing,Hg2+ sensors,optical sensors,ecosafety,plasmonic sensors
更新于2025-09-12 10:27:22
-
Multi-Purpose Nanovoid Array Plasmonic Sensor Produced by Direct Laser Patterning
摘要： We demonstrate a multi-purpose plasmonic sensor based on a nanovoid array fabricated via inexpensive and highly-reproducible direct femtosecond laser patterning of thin glass-supported Au films. The proposed nanovoid array exhibits near-IR surface plasmon (SP) resonances, which can be excited under normal incidence and optimised for specific applications by tailoring the array periodicity, as well as the nanovoid geometric shape. The fabricated SP sensor offers competitive sensitivity of ≈ 1600 nm/RIU at a figure of merit of 12 in bulk refractive index tests, as well as allows for identification of gases and ultra-thin analyte layers, making the sensor particularly useful for common bioassay experiments. Moreover, isolated nanovoids support strong electromagnetic field enhancement at lattice SP resonance wavelength, allowing for label-free molecular identification via surface-enhanced vibration spectroscopy.
关键词： refractive index and gas sensing,nanovoid arrays,direct femtosecond laser printing,plasmonic sensors
更新于2025-09-12 10:27:22
-
Self‐Assembled Polyamidoamine Dendrimer on Poly (methyl meth‐ acrylate) for Plasmonic Fiber Optic Sensors
摘要： We report a novel one-step polyamidoamine (PAMAM) dendrimer based polymethyl methacrylate (PMMA) surface functionalization strategy for the development of polymeric optical (POF) based plasmonic sensors utilizing gold nanoparticles (AuNP). Simple contact angle measurements over PMMA sheets reveal the ability of the dendrimers to strongly bind to PMMA surface without additional acid/alkali pretreatment, unlike the conventional hexamethylene diamine (HMDA) based surface modification. Subsequently, U-bent POF probes with high evanescent wave absorbance sensitivity were exploited for relative quantification of the surface amine groups using fluorescein isothiocyanate (FITC) binding and efficient chemisorption of gold nanoparticles (AuNP) in order to identify the optimum conditions viz. dendrimer concentration, incubation time and dendrimer generation. While FITC binding showed a proportional increase in amine functional density with PAMAM concentration and time, interestingly the AuNP (40 nm) binding studies revealed the formation of loose PAMAM multilayers and their desorption. PAMAM (G4) concentration as low as 5 mM and incubation time of 24 h provide faster binding rate with densely packed AuNP and the RI sensitivity of ~ 15 (A546 nm/RIU). This simpler and inexpensive strategy could also be exploited for the development of functional PMMA substrates for various applications including nanotechnology, bio-imaging, drug delivery and analytical separations.
关键词： gold nanoparticles (AuNP),dendrimers,plasmonic sensors,polymethyl methacrylate (PMMA),polymeric optical fibers (POF),evanescent wave absorbance
更新于2025-09-11 14:15:04
-
A disposable microfluidic-integrated hand-held plasmonic platform for protein detection
摘要： Healthcare is in the midst of a transformative shift from centralized care to point-of-care (POC). In this regard, recent efforts have focused on integration of biosensing technologies with clinical management and existing healthcare systems to improve the effectiveness and quality of care. Plasmonic technologies in particular, have been used for multiple applications in biosensing, pharmaceutical industry, food quality monitoring, and healthcare. However, bulky-sized platforms, expensive instrumentation, incomprehensive benchmarking, laborious protocols, and time-consuming processing steps remain challenges to adopt biosensing platforms to the POC settings. Here, we present a hand-held biosensing platform that integrates a plasmonic detection modality with a microfluidic chip. As a biological target model, we assess hemoglobin—an iron carrying protein in red blood cells. We comprehensively perform theoretical simulations and kinetic calculations to benchmark the platform performance. Overall, this miniaturized platform provides label-free detection, simple configuration for user-interface, facile sampling, assay-time down to 15–30 min, and inexpensive disposable chips. Therefore, this platform will potentially accelerate the deployment of portable biosensing systems for the POC and primary care settings.
关键词： Microfluidics,Point-of-care,Plasmonic sensors,Hemoglobin,Portable biosensors
更新于2025-09-11 14:15:04
-
Infiltrated Photonic Crystal Fibers for Sensing Applications
摘要： Photonic crystal ?bers (PCFs) are a special class of optical ?bers with a periodic arrangement of microstructured holes located in the ?ber’s cladding. Light con?nement is achieved by means of either index-guiding, or the photonic bandgap effect in a low-index core. Ever since PCFs were ?rst demonstrated in 1995, their special characteristics, such as potentially high birefringence, very small or high nonlinearity, low propagation losses, and controllable dispersion parameters, have rendered them unique for many applications, such as sensors, high-power pulse transmission, and biomedical studies. When the holes of PCFs are ?lled with solids, liquids or gases, unprecedented opportunities for applications emerge. These include, but are not limited in, supercontinuum generation, propulsion of atoms through a hollow ?ber core, ?ber-loaded Bose–Einstein condensates, as well as enhanced sensing and measurement devices. For this reason, in?ltrated PCF have been the focus of intensive research in recent years. In this review, the fundamentals and fabrication of PCF in?ltrated with different materials are discussed. In addition, potential applications of in?ltrated PCF sensors are reviewed, identifying the challenges and limitations to scale up and commercialize this novel technology.
关键词： optical fiber sensors,photonic crystal fibers,optofluidics,plasmonic sensors,liquid crystals
更新于2025-09-09 09:28:46