scholarly journals Fabrication of Humidity-Resistant Optical Fiber Sensor for Ammonia Sensing Using Diazo Resin-Photocrosslinked Films with a Porphyrin-Polystyrene Binary Mixture

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6176 ◽  
Author(s):  
Soad Ahmed ◽  
Yeawon Park ◽  
Hirofumi Okuda ◽  
Shoichiro Ono ◽  
Sergiy Korposh ◽  
...  
Keyword(s):  
Binary Mixture ◽  
Optical Fiber ◽  
Limit Of Detection ◽  
Sensor Response ◽  
Fiber Sensor ◽  
Layer By Layer ◽  
Film Sensor ◽  
Covalent Bonds ◽  
Ammonia Gas ◽  
Hydrophobic Moiety

Ammonia gas sensors were fabricated via layer-by-layer (LbL) deposition of diazo resin (DAR) and a binary mixture of tetrakis(4-sulfophenyl)porphine (TSPP) and poly(styrene sulfonate) (PSS) onto the core of a multimode U-bent optical fiber. The penetration of light transferred into the evanescent field was enhanced by stripping the polymer cladding and coating the fiber core. The electrostatic interaction between the diazonium ion in DAR and the sulfonate residues in TSPP and PSS was converted into covalent bonds using UV irradiation. The photoreaction between the layers was confirmed by UV-vis and Fourier transform infrared spectroscopy. The sensitivity of the optical fiber sensors to ammonia was linear when exposed to ammonia gases generated from aqueous ammonia solutions at a concentration of approximately 17 parts per million (ppm). This linearity extended up to 50 ppm when the exposure time (30 s) was shortened. The response and recovery times were reduced to 30 s with a 5-cycle DAR/TSPP+PSS (as a mixture of 1 mM TSPP and 0.025 wt% PSS in water) film sensor. The limit of detection (LOD) of the optimized sensor was estimated to be 0.31 ppm for ammonia in solution, corresponding to approximately 0.03 ppm of ammonia gas. It is hypothesized that the presence of the hydrophobic moiety of PSS in the matrix suppressed the effects of humidity on the sensor response. The sensor response was stable and reproducible over seven days. The PSS-containing U-bent fiber sensor also showed superior sensitivity to ammonia when examined alongside amine and non-amine analytes.

scholarly journals Development of an Aptamer Based Luminescent Optical Fiber Sensor for the Continuous Monitoring of Hg2+ in Aqueous Media

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2372 ◽  
Author(s):  
Nerea De Acha ◽  
César Elosúa ◽  
Francisco J. Arregui
Keyword(s):  
Optical Fiber ◽  
Aqueous Solutions ◽  
Limit Of Detection ◽  
Tap Water ◽  
Aqueous Media ◽  
Optical Fiber Sensor ◽  
Fluorescence Emission ◽  
Fiber Sensor ◽  
Buffer Solution ◽  
Fluorescence Quencher

A fluorescent optical fiber sensor for the detection of mercury (Hg2+) ions in aqueous solutions is presented in this work. The sensor was based on a fluorophore-labeled thymine (T)-rich oligodeoxyribonucleotide (ON) sequence that was directly immobilized onto the tip of a tapered optical fiber. In the presence of mercury ions, the formation of T–Hg2+-T mismatches quenches the fluorescence emission by the labeled fluorophore, which enables the measurement of Hg2+ ions in aqueous solutions. Thus, in contrast to commonly designed sensors, neither a fluorescence quencher nor a complementary ON sequence is required. The sensor presented a response time of 24.8 seconds toward 5 × 10−12 M Hg2+. It also showed both good reversibility (higher than the 95.8%) and selectivity: the I0/I variation was 10 times higher for Hg2+ ions than for Mn2+ ions. Other contaminants examined (Co2+, Ag+, Cd2+, Ni2+, Ca2+, Pb2+, Mn2+, Zn2+, Fe3+, and Cu2+) presented an even lower interference. The limit of detection of the sensor was 4.73 × 10−13 M Hg2+ in buffer solution and 9.03 × 10−13 M Hg2+ in ultrapure water, and was also able to detect 5 × 10−12 M Hg2+ in tap water.

An Optical Fiber Sensor for Hg2+ Detection Based on the LSPR of Silver and Gold Nanoparticles Embedded in a Polymeric Matrix as an Effective Sensing Material

2021 ◽  
Vol 5 (1) ◽  
pp. 73
Author(s):  
María Elena Martínez-Hernández ◽  
Xabier Sandua ◽  
Pedro J. Rivero ◽  
Javier Goicoechea ◽  
Francisco J. Arregui
Keyword(s):  
Gold Nanoparticles ◽  
Optical Fiber ◽  
Localized Surface Plasmon Resonance ◽  
Spectral Response ◽  
Optical Fiber Sensor ◽  
Fiber Sensor ◽  
Localized Surface Plasmon ◽  
Layer By Layer ◽  
Sensing Material ◽  
Reliable Monitoring

In this work, an optical fiber sensor based on the localized surface plasmon resonance (LSPR) phenomenon is presented as a powerful tool for the detection of heavy metals (Hg2+). The resultant sensing film was fabricated using a nanofabrication process, known as layer-by-layer embedding (LbL-E) deposition technique. In this sense, both silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) were synthesized using a synthetic chemical protocol as a function of a strict control of three main parameters: polyelectrolyte concentration, loading agent, and reducing agent. The use of metallic nanostructures as sensing materials is of great interest because well-located absorption peaks associated with their LSPR are obtained at 420 nm (AgNPs) and 530 nm (AuNPs). Both plasmonic peaks provide a stable real-time reference that can be extracted from the spectral response of the optical fiber sensor, giving a reliable monitoring of the Hg2+ concentration.

Particle size effects on an optical fiber sensor response

2001 ◽  
Vol 115 (1) ◽  
pp. 68-74 ◽  
Author(s):  
I Bellino ◽  
L Bergougnoux ◽  
J Misguich-Ripault ◽  
J.-L Firpo
Keyword(s):  
Particle Size ◽  
Optical Fiber ◽  
Size Effects ◽  
Optical Fiber Sensor ◽  
Sensor Response ◽  
Fiber Sensor ◽  
Particle Size Effects

scholarly journals Self-Referenced Optical Fiber Sensor for Hydrogen Peroxide Detection based on LSPR of Metallic Nanoparticles in Layer-by-Layer Films

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3872 ◽  
Author(s):  
Goicoechea ◽  
Rivero ◽  
Sada ◽  
Arregui
Keyword(s):  
Hydrogen Peroxide ◽  
Optical Fiber ◽  
Metallic Nanoparticles ◽  
Low Cost ◽  
Spectral Response ◽  
Optical Fiber Sensor ◽  
Fiber Sensor ◽  
Localized Surface Plasmon ◽  
Layer By Layer ◽  
Robust Detection

Intensity-based optical fiber sensors are one of the most studied sensor approaches thanks to their simplicity and low cost. Nevertheless, their main issue is their lack of robustness since any light source fluctuation, or unexpected optical setup variation is directly transferred to the output signal, which, significantly reduces their reliability. In this work, a simple and robust hydrogen peroxide (H2O2) optical fiber sensor is proposed based on the Localized Surface Plasmon Resonance (LSPR) sensitivity of silver and gold metallic nanoparticles. The precise and robust detection of H2O2 concentrations in the ppm range is very interesting for the scientific community, as it is a pathological precursor in a wide variety of damage mechanisms where its presence can be used to diagnose important diseases such as Parkinson’s disease, diabetes, asthma, or even Alzheimer’s disease). In this work, the sensing principle is based the oxidation of the silver nanoparticles due the action of the hydrogen peroxide, and consequently the reduction of the efficiency of the plasmonic coupling. At the same time, gold nanoparticles show a high chemical stability, and therefore provide a stable LSPR absorption band. This provides a stable real-time reference that can be extracted from the spectral response of the optical fiber sensor, giving a reliable reading of the hydrogen peroxide concentration.

scholarly journals A long period grating optical fiber sensor with nano-assembled porphyrin layers for detecting ammonia gas

2016 ◽  
Vol 228 ◽  
pp. 573-580 ◽  
Author(s):  
Tao Wang ◽  
Wataru Yasukochi ◽  
Sergiy Korposh ◽  
Stephen W. James ◽  
Ralph P. Tatam ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Optical Fiber Sensor ◽  
Fiber Sensor ◽  
Long Period Grating ◽  
Ammonia Gas ◽  
Long Period
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