Volatile Organic Compounds Sensing Using Optical Fibre Long Period Grating with Mesoporous Nano-Scale Coating

Here, we present a novel method to fabricate long period gratings using standard single mode optical fibers (SMF). These optical devices were fabricated in a three-step process, which consisted of etching the SMF, then coating it with a thin-film and, the final step, which involved removing sections of the coating periodically by laser ablation. Tin dioxide was chosen as the material for this study and it was sputtered using a pulsed DC sputtering system. Theoretical simulations were performed in order to select the appropriate parameters for the experiments. The responses of two different devices to different external refractive indices was studied, and the maximum sensitivity obtained was 6430 nm/RIU for external refractive indices ranging from 1.37 to 1.39.

at 1280 nm when it was immersed in a medium with a SMRI of 1.347.…”

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Fabrication of Long Period Gratings by Periodically Removing the Coating of Cladding-Etched Single Mode Optical Fiber Towards Optical Fiber Sensor Development

Ascorbe

Corres

Villar

et al. 2018

“…The sensing mechanism is based on the measurement of the refractive index change induced by the complexation of the VOCs with the CA[4] receptor. This same sensing mechanism has been used in [132], although in this work two different sizes of calixarene molecules such as CA[4] and CA[8], respectively, have been employed for the detection of individual VOCs and their mixtures evaporating from freshly painted surfaces. The experimental results indicate that although neither of the sensors can discriminate between individual VOCs, a different response has been observed to two different commercial paint products, suggesting that the sensors can distinguish between different mixtures.…”

Section: Applications Of the Optical Fiber Sensors Based On Layer-mentioning

confidence: 99%

“…( a ) CA[8] and ( b ) CA[4] Sensor’s response related to towards selected VOCs at different concentration levels (the error bars represent the standard deviation). Reprinted from [132] with permission.…”

Section: Figurementioning

confidence: 99%

Layer-by-Layer Nano-assembly: A Powerful Tool for Optical Fiber Sensing Applications

Rivero

Goicoechea

Arregui

2019

The ability to tune the composition of nanostructured thin films is a hot topic for the design of functional coatings with advanced properties for sensing applications. The control of the structure at the nanoscale level enables an improvement of intrinsic properties (optical, chemical or physical) in comparison with the traditional bulk materials. In this sense, among all the known nanofabrication techniques, the layer-by-layer (LbL) nano-assembly method is a flexible, easily-scalable and versatile approach which makes possible precise control of the coating thickness, composition and structure. The development of sensitive nanocoatings has shown an exceptional growth in optical fiber sensing applications due to their self-assembling ability with oppositely charged components in order to obtain a multilayer structure. This nanoassembly technique is a powerful tool for the incorporation of a wide variety of species (polyelectrolytes, metal/metal oxide nanoparticles, hybrid particles, luminescent materials, dyes or biomolecules) in the resultant multilayer structure for the design of high-performance optical fiber sensors. In this work we present a review of applications related to optical fiber sensors based on advanced LbL coatings in two related research areas of great interest for the scientific community, namely chemical sensing (pH, gases and volatile organic compounds detection) as well as biological/biochemical sensing (proteins, immunoglobulins, antibodies or DNA detection).

“…Furthermore, the fibre can be dipped into solutions with a sensing material to functionalize the supporting matrix in a way that compound is trapped into the porous layer once the fibre is removed from the solution [ 96 ]. As a result, bio sensors concentration have been implemented to measure immunoglobulins in terms of the Bragg wavelength shift produced by the transduction [ 97 ]; devices to detect VOCs have been also reported using LPGs coated with sol gel functionalized by calixalane [ 98 ]. Other hybrid sol gel compounds that handle with gold nanoparticles are currently be under study for luminescent based sensing applications [ 99 ].…”

Section: Nano and Microstructured Materials For Sensingmentioning

confidence: 99%

Micro and Nanostructured Materials for the Development of Optical Fibre Sensors

Elosúa

Arregui

Villar

et al. 2017

The measurement of chemical and biomedical parameters can take advantage of the features exclusively offered by optical fibre: passive nature, electromagnetic immunity and chemical stability are some of the most relevant ones. The small dimensions of the fibre generally require that the sensing material be loaded into a supporting matrix whose morphology is adjusted at a nanometric scale. Thanks to the advances in nanotechnology new deposition methods have been developed: they allow reagents from different chemical nature to be embedded into films with a thickness always below a few microns that also show a relevant aspect ratio to ensure a high transduction interface. This review reveals some of the main techniques that are currently been employed to develop this kind of sensors, describing in detail both the resulting supporting matrices as well as the sensing materials used. The main objective is to offer a general view of the state of the art to expose the main challenges and chances that this technology is facing currently.