In situ growth of Au–Ag bimetallic nanorings on optical fibers for enhanced plasmonic sensing

2020 ◽  
Vol 8 (22) ◽  
pp. 7552-7560 ◽  
Author(s):  
Se Shi ◽  
Anran Li ◽  
Renliang Huang ◽  
Jing Yu ◽  
Shuzhou Li ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Oxidation Resistance ◽  
Optical Fibers ◽  
Fiber Surface ◽  
Metal Deposition ◽  
In Situ Growth ◽  
Plasmonic Sensing

Au–Ag bimetallic nanorings were grown in situ on an optical fiber surface via bioinspired PDA, a synergetic GRR and metal deposition, which exhibited enhanced LSPR sensitivity and oxidation resistance.

scholarly journals Polydopamine-Assisted Fabrication of Stable Silver Nanoparticles on Optical Fiber for Enhanced Plasmonic Sensing

2019 ◽  
Vol 10 (2) ◽  
pp. 97-104 ◽  
Author(s):  
Yiwen Tang ◽  
Hui Yuan ◽  
Jiangping Chen ◽  
Qiguo Xing ◽  
Rongxin Su ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Localized Surface Plasmon Resonance ◽  
Optical Fiber Sensor ◽  
Redox Activity ◽  
Fiber Sensor ◽  
Localized Surface Plasmon ◽  
Future Application ◽  
Ag Nps ◽  
Plasmonic Sensing

Abstract We present a facile and effective method for fabrication of the localized surface plasmon resonance (LSPR) optical fiber sensor assisted by two polydopamine (PDA) layers with enhanced plasmonic sensing performance. The first PDA layer was self-polymerized onto the bare optical fiber to provide the catechol groups for the reduction from Ag+ to Ago through chelating and redox activity. As the reduction of Ag+ proceeds, Ag nanoparticles (NPs) were grown in-situ on the PDA layer with uniform distribution. The second PDA layer was applied to prevent Ag NPs from oxidating and achieve an improvement of LSPR signal. The PDA/Ag/PDA-based optical fiber sensor has an enhanced LSPR sensitivity of 961 nm/RIU and excellent oxidation resistance. The stable PDA/Ag/PDA-based LSPR sensor with high optical performance is very promising for future application in optical sensing field.

scholarly journals An Optical Fiber Chemical Sensor for the Detection of Copper(II) in Drinking Water

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5246 ◽  
Author(s):  
Pesavento ◽  
Profumo ◽  
Merli ◽  
Cucca ◽  
Zeni ◽  
...  
Keyword(s):  
Drinking Water ◽  
Optical Fiber ◽  
Optical Fibers ◽  
Chemical Sensor ◽  
Low Cost ◽  
Self Assembled Monolayer ◽  
Ph Values ◽  
Highly Sensitive ◽  
Selective Sensor

Highly sensitive plasmonic optical fiber platforms combined with receptors have been recently used to obtain selective sensors. A low-cost configuration can be obtained exploiting a D-shaped plastic optical fiber covered with a multilayer sensing surface. The multilayer consists of a gold film, functionalized with a specific receptor, where the surface plasmon resonance (SPR) occurs. The signal is produced by the refractive index variation occurring as a consequence of the receptor-to analyte binding. In this work, a selective sensor for copper(II) detection in drinking water, exploiting a self-assembled monolayer (SAM) of d,l-penicillamine as the sensing layer, has been developed and tested. Different concentrations of copper(II) in NaCl 0.1 M solutions at different pH values and in a real matrix (drinking water) have been considered. The results show that the sensor is able to sense copper(II) at concentrations ranging from 4 × 10-6 M to 2 × 10-4 M. The use of this optical chemical sensor is a very attractive perspective for fast, in situ and low-cost detection of Cu(II) in drinking water for human health concerns. Furthermore, the possibility of remote control is feasible as well, because optical fibers are employed.

Optical Fiber-Based Wave Mixing as a Convenient and Sensitive Laser Analytical Tool for Condensed-Phase Analytes

1998 ◽  
Vol 52 (5) ◽  
pp. 763-769 ◽  
Author(s):  
Jon A. Nunes ◽  
William G. Tong
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Condensed Phase ◽  
Spectroscopic Method ◽  
Spectroscopic Technique ◽  
Wave Mixing ◽  
Small Probe ◽  
Highly Sensitive ◽  
Optical Alignment

A fiber-optic degenerate four-wave mixing (D4WM) probe for the measurement of small absorptions in liquid-phase samples is described. Laser D4WM is a nonlinear laser spectroscopic technique that has proven to be highly sensitive for the detection of trace analytes in condensed-phase media. A significant improvement in the forward-scattering optical arrangement of D4WM is demonstrated by using optical fibers for both laser light input and output. There is considerable flexibility inherent in the design since the system may be used in three configurations: (1) the simplest case of transmitting the signal radiation by optical fiber to the detection electronics, (2) the case of guiding the excitation beams to the analyte by polarization-maintaining optical fibers, and (3) the combination of both. The optical fiber-based D4WM system is shown to be an effective and sensitive laser analytical spectroscopic method for trace analysis, offering advantages such as detection in very small probe volumes, remote and in situ analysis, and convenient and efficient optical alignment enhancements obtained by the use of optical fibers.

scholarly journals Binding Analysis of Functionalized Multimode Optical-Fiber Sandwich-like Structure with Organic Polymer and Its Sensing Application for Humidity and Breath Monitoring

Biosensors ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 324
Author(s):  
Daniel Jauregui-Vazquez ◽  
Paulina Lozano-Sotomayor ◽  
Jorge Emmanuel Mejía-Benavides ◽  
Erik Díaz-Cervantes
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Molecular System ◽  
Low Cost ◽  
Computational Simulation ◽  
Fiber Surface ◽  
Cost Effective ◽  
Effective Alternative ◽  
Organic Polymer ◽  
Cost Effective Alternative

In recent years, the chemical modification of optical fibers (OFs) has facilitated the manufacture of sensors because OFs can identify several analytes present in aqueous solutions or gas phases. Nevertheless, it is imperative better to understand the chemical interactions in this molecular system to generate low-cost and efficient sensors. This work presents a theoretical and experimental study of organic polymeric functionalized OF structures and proposes a cost-effective alternative to monitor breathing and humidity. The device is based on silicon optical fibers functionalized with (3-Aminopropyl) triethoxysilane (APTES) and alginate. The theoretical analysis is carried out to validate the activation of the silicon dioxide fiber surface; moreover, the APTES–alginate layer is discussed. The computational simulation suggests that water can be absorbed by alginate, specifically by the calcium atom linked to the carboxylic acid group of the alginate. The analysis also demonstrates a higher electrostatic interaction between the water and the OF–APTES–alginate system; this interaction alters the optical fiber activated surface’s refractive index, resulting in transmission power variation. The humidity analysis shows a sensitivity of 3.1288 mV/RH, a time response close to 25 s, and a recovery time around 8 s. These results were achieved in the range of 50 to 95% RH. Moreover, the recovery and response time allow the human breath to be studied. The proposed mechanism or device is competitive with prior works, and the components involved made this sensor a cost-effective alternative for medical applications.

scholarly journals Use of Optical Fiber Sensor for Monitoring the Degradation of Ac-Dex Biopolymeric Nanoparticles

Proceedings ◽  
2019 ◽  
Vol 42 (1) ◽  
pp. 12
Author(s):  
Marco César Prado Soares ◽  
Gabriel Perli ◽  
Matheus Kauê Gomes ◽  
Carolyne Brustolin Braga ◽  
Diego Luan Bertuzzi ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Optical Fibers ◽  
Optical Fiber Sensor ◽  
Single Mode ◽  
Spherical Particles ◽  
Fiber Sensor ◽  
Elastic Light Scattering ◽  
Modified Polymer ◽  
Degradation Pattern

Abstract: Acetalated dextran (Ac-Dex) is a promising pH-sensitive biocompatible and biodegradable polymer for nanomedicine applications. In this work, Ac-Dex nanoparticles were synthesized by two different solvent evaporation methods, the single nanoemulsion and the double nanoemulsion. The Ac-Dex particles were characterized by scanning electron microscopy and the synthesis of highly homogeneous spherical particles was verified. Then, an optical fiber sensor based on quasi-elastic light scattering and comprised of only single-mode optical fibers and standard telecommunication devices showed sensitivity regarding the nanoparticles concentrations and was used for monitoring their degradation over 12 h under pH and temperature conditions of cancerous tissues. The results revealed a well-controlled degradation pattern, corroborating the suitability of the modified polymer to the release of active compounds in a sustainable manner and also demonstrating the applicability of the sensor for the in situ evaluation of the degradation.

In-situ growth of AuNPs on WS2@U-bent optical fiber for evanescent wave absorption sensor

2018 ◽  
Vol 441 ◽  
pp. 1072-1078 ◽  
Author(s):  
Suzhen Zhang ◽  
Yuefeng Zhao ◽  
Chao Zhang ◽  
Shouzhen Jiang ◽  
Cheng Yang ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Evanescent Wave ◽  
In Situ Growth ◽  
Wave Absorption

SEM of non-coated hepatocellular cytoskeleton of perfused livers

1984 ◽  
Vol 42 ◽  
pp. 306-307
Author(s):  
S.W. French ◽  
N.C. Benson ◽  
C. Davis-Scibienski
Keyword(s):  
Ambient Temperature ◽  
Critical Point ◽  
Protease Inhibitors ◽  
Metal Deposition ◽  
Heat Damage ◽  
Detergent Extraction ◽  
Cytoskeletal Elements ◽  
Triton X ◽  
Excised Tissue

Previous SEM studies of liver cytoskeletal elements have encountered technical difficulties such as variable metal coating and heat damage which occurs during metal deposition. The majority of studies involving evaluation of the cell cytoskeleton have been limited to cells which could be isolated, maintained in culture as a monolayer and thus easily extracted. Detergent extraction of excised tissue by immersion has often been unsatisfactory beyond the depth of several cells. These disadvantages have been avoided in the present study. Whole C3H mouse livers were perfused in situ with 0.5% Triton X-100 in a modified Jahn's buffer including protease inhibitors. Perfusion was continued for 1 to 2 hours at ambient temperature. The liver was then perfused with a 2% buffered gluteraldehyde solution. Liver samples including spontaneous tumors were then maintained in buffered gluteraldehyde for 2 hours. Samples were processed for SEM and TEM using the modified thicarbohydrazide procedure of Malich and Wilson, cryofractured, and critical point dried (CPD). Some samples were mechanically fractured after CPD.

Epitaxial growth manner and structure of superconducting oxide films

1990 ◽  
Vol 48 (4) ◽  
pp. 2-3
Author(s):  
Yoshichika Bando ◽  
Takahito Terashima ◽  
Kenji Iijima ◽  
Kazunuki Yamamoto ◽  
Kazuto Hirata ◽  
...  
Keyword(s):  
Ultrathin Films ◽  
Film Surface ◽  
High Energy ◽  
Epitaxial Films ◽  
Layer By Layer ◽  
Initial Growth ◽  
In Situ Growth ◽  
High Quality ◽  
Activated Reactive Evaporation

The high quality thin films of high-Tc superconducting oxide are necessary for elucidating the superconducting mechanism and for device application. The recent trend in the preparation of high-Tc films has been toward “in-situ” growth of the superconducting phase at relatively low temperatures. The purpose of “in-situ” growth is to attain surface smoothness suitable for fabricating film devices but also to obtain high quality film. We present the investigation on the initial growth manner of YBCO by in-situ reflective high energy electron diffraction (RHEED) technique and on the structural and superconducting properties of the resulting ultrathin films below 100Å. The epitaxial films have been grown on (100) plane of MgO and SrTiO, heated below 650°C by activated reactive evaporation. The in-situ RHEED observation and the intensity measurement was carried out during deposition of YBCO on the substrate at 650°C. The deposition rate was 0.8Å/s. Fig. 1 shows the RHEED patterns at every stage of deposition of YBCO on MgO(100). All the patterns exhibit the sharp streaks, indicating that the film surface is atomically smooth and the growth manner is layer-by-layer.

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