Evanescent wave optical fibre ammonia sensor with methylamine hydroiodide

Subashini, T.; Paramasivan, Chandrasekar; Renganathan, B.; Prakash, T.

doi:10.1049/iet-opt.2019.0144

Cited by 6 publications

(3 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The partial internal reflection occurs inside the core, and light refracts into the SnO 2 layer (interface 1). The refracted light in the SnO 2 layer reaches interface 2 due to total internal reflection between the SnO 2 thin film and air ambiance [ 23 ]. The proposed sensing layer can absorb light although it is a transparent material [ 24 ].…”

Section: Methodsmentioning

confidence: 99%

A Bilayer SnO2/MoS2-Coated Evanescent Wave Fiber Optic Sensor for Acetone Detection—An Experimental Study

et al. 2022

View full text Add to dashboard Cite

The need for sensors that measure the acetone content of exhaled breath for diabetes severity has recently increased. Clinical researchers have reported less than 0.8 ppm acetone concentration in the exhaled breath of an average individual, while that for a diabetic patient is higher than 1.8 ppm. This work reports the development of two sets of evanescent wave-based fiber optic sensor coated with SnO2 thin film and bilayer of SnO2/MoS2 to detect different acetone concentrations (0–250 ppm). In each set, we have studied the effect of clad thickness (chemical etch time 5min, 10 min, 15 min, 25 min, 40 min, and complete clad removal) to optimize the clad thickness for a better response. In Set 1, SnO2 thin film was used as the sensing layer, while in Set 2 a bilayer of SnO2 thin film/ MoS2 was used. Enhanced sensor response of ~23.5% is observed in the Set 2 probe with a response and recovery time of ~14 s/~17 s. A SnO2/MoS2-coated sensor prototype is developed using LEDs of different wavelength and intensity detector; its potential to detect different concentrations of acetone is tested. X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), Ultraviolet (UV) Spectroscopy, and Ellipsometry were used to study the structural, morphological and optical properties of the sensing layers. The present study indicates that the SnO2/MoS2-coated sensor has the potential to create a handheld sensor system for monitoring diabetes.

show abstract

Section: Methodsmentioning

confidence: 99%

A Bilayer SnO2/MoS2-Coated Evanescent Wave Fiber Optic Sensor for Acetone Detection—An Experimental Study

et al. 2022

View full text Add to dashboard Cite

show abstract

“…As it will be shown later, the dye (AAF + perylene red) becomes coated on the side of fibre during the functionalization process; however, it should be noted that only the dye present on the tip of the optical fibre participates in the creation of a pH-sensitive signal-not the dye present on the side of the fibre-as the sensing mechanism is not, in this case, based on the modification of the evanescent wave 'tail' (a technique previously reported in the operation of several evanescent wave-based sensors [60][61][62]). Thus, the optical fibre is only acting as a passive element, i.e., carrying the light from the source to the dye and then from the dye to the spectrometer.…”

Section: Principle Of Operationmentioning

confidence: 99%

A Portable ‘Plug-and-Play’ Fibre Optic Sensor for In-Situ Measurements of pH Values for Microfluidic Applications

et al. 2022

View full text Add to dashboard Cite

Microfluidics is used in many applications ranging from chemistry, medicine, biology and biomedical research, and the ability to measure pH values in-situ is an important parameter for creating and monitoring environments within a microfluidic chip for many such applications. We present a portable, optical fibre-based sensor for monitoring the pH based on the fluorescent intensity change of an acrylamidofluorescein dye, immobilized on the tip of a multimode optical fibre, and its performance is evaluated in-situ in a microfluidic channel. The sensor showed a sigmoid response over the pH range of 6.0–8.5, with a maximum sensitivity of 0.2/pH in the mid-range at pH 7.5. Following its evaluation, the sensor developed was used in a single microfluidic PDMS channel and its response was monitored for various flow rates within the channel. The results thus obtained showed that the sensor is sufficiently robust and well-suited to be used for measuring the pH value of the flowing liquid in the microchannel, allowing it to be used for a number of practical applications in ‘lab-on-a-chip’ applications where microfluidics are used. A key feature of the sensor is its simplicity and the ease of integrating the sensor with the microfluidic channel being probed.

show abstract

“…Therefore, PDIs are promising materials for the development of optical sensors for ammonia detection. In recent years, several authors presented high sensitivity ammonia sensors based on functionalized optical fibers applied to detect ammonia in gas phase and liquid solution [12][13][14][15][16][17] A recent review of fiber optic sensors for gases, vapors and ions can be found at [18]. Fiber Bragg gratings are a class of optical sensors that have attracted attention of researchers in recent decades due to properties such as wavelength coding, multipoint remote sensing, electrical passivity and electromagnetic immunity.…”

Section: Introductionmentioning

confidence: 99%

Induced Birefringence by Drop Cast in EFBG Ammonia Sensors

et al. 2021

View full text Add to dashboard Cite

In this paper, an induced birefringence was observed on an ammonia sensor based on an etched fiber Bragg grating (EFBG) coated with an organic film. The film was prepared with a solution of the perylene derivative, along with the copolymer PCDTBT in chlorobenzene. The EFBG was coated by drop cast technique, and a split in the reflection band, characteristic of birefringence, was observed after deposition. The response of the two observed peaks as a function of time was modeled by a pair of exponentials that could represent two processes: adsorption followed by diffusion of the gas molecules in the microstructured film. Such phenomena alter the boundary conditions of the optical fiber propagating mode, which allows an indirect ammonia detection by monitoring the EFBG wavelength shift of the reflected peaks. The sensor was experimentally tested in a concentration range from 3 ppm to 41,700 ppm, and the calibrations curves were determined in a range from 27 ppm to 6960 ppm. The two observed peaks showed different sensitivities, which presents an intrinsic potential for multiparameter measurements. The split in the reflection band was hypothesized to be birefringence induced by the formation of an asymmetric film. This hypothesis was numerically evaluated and compared with the experimental results.

show abstract

Evanescent wave optical fibre ammonia sensor with methylamine hydroiodide

Cited by 6 publications

References 19 publications

A Bilayer SnO2/MoS2-Coated Evanescent Wave Fiber Optic Sensor for Acetone Detection—An Experimental Study

A Bilayer SnO2/MoS2-Coated Evanescent Wave Fiber Optic Sensor for Acetone Detection—An Experimental Study

A Portable ‘Plug-and-Play’ Fibre Optic Sensor for In-Situ Measurements of pH Values for Microfluidic Applications

Induced Birefringence by Drop Cast in EFBG Ammonia Sensors

Contact Info

Product

Resources

About