scholarly journals Etched Fiber Bragg Grating Biosensor Functionalized with Aptamers for Detection of Thrombin

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4298 ◽  
Author(s):  
Aliya Bekmurzayeva ◽  
Kanat Dukenbayev ◽  
Madina Shaimerdenova ◽  
Ildar Bekniyazov ◽  
Takhmina Ayupova ◽  
...  
Keyword(s):  
Refractive Index ◽  
Fiber Bragg Grating ◽  
Chemical Vapor ◽  
Bragg Grating ◽  
Clinical Settings ◽  
Long Period Grating ◽  
Bragg Wavelength ◽  
Sensing System ◽  
Index Unit

A biosensor based on an etched Fiber Bragg Grating (EFBG) for thrombin detection is reported. The sensing system is based on a Fiber Bragg Grating (FBG) with a Bragg wavelength of 1550 nm, wet-etched in hydrofluoric acid (HF) for ~27 min, to achieve sensitivity to a refractive index (RI) of 17.4 nm/RIU (refractive index unit). Subsequently, in order to perform a selective detection of thrombin, the EFBG has been functionalized with silane-coupling agent 3-(aminopropyl)triethoxysilane (APTES) and a cross-linker, glutaraldehyde, for the immobilization of thrombin-binding aptamer. The biosensor has been validated for thrombin detection in concentrations ranging from 10 nM to 80 nM. The proposed sensor presents advantages with respect to other sensor configurations, based on plasmonic resonant tilted FBG or Long Period Grating (LPG), for thrombin detection. Firstly, fabricating an EFBG only requires chemical etching. Moreover, the functionalization method used in this study (silanization) allows the avoidance of complicated and expensive fabrications, such as thin film sputtering or chemical vapor deposition. Due to their characteristics, EFBG sensors are easier to multiplex and can be used in vivo. This opens new possibilities for the detection of thrombin in clinical settings.

Design of a Sensor System Using Fiber Bragg Grating for Liquid Level and Liquid Density Measurement

2020 ◽  
Vol 18 (12) ◽  
pp. 889-893
Author(s):  
Kalyan Biswas
Keyword(s):  
Fiber Bragg Grating ◽  
Density Measurement ◽  
Sensor System ◽  
Liquid Level ◽  
Bragg Grating ◽  
Liquid Density ◽  
Bragg Wavelength ◽  
Sensing System ◽  
System A ◽  
Level Monitoring

In this work, a simple but versatile sensing system for very accurate sensing of liquid level and liquid density is presented. The sensor works based on basic strain sensitivity of Fiber Bragg Grating (FBG) and principle of liquid obeying Archimedes’ law of buoyancy. In this system, a cylindrical shaped mass suspended from a Fiber Bragg Grating and partially immersed in the liquid to be sensed. If the liquid level in the container or liquid density varies, that change the up thrust on the suspended mass and load on the Fiber will be changed accordingly. The change in the load on Fiber changes strain on the FBG and the reflected Bragg wavelength also changes. The proposed device with proper calibration should be able to carry out real time and nonstop liquid level and liquid density measurements. A mathematical analysis of the system considering liquid properties and geometrical structure of the suspended mass is presented here. Sensitivity of the system for liquid level monitoring is also reported. Achieved results shows the path for the utilization of the proposed sensor system for precise liquid density measurement and liquid level sensing in very large storage tanks used for commercial/residential applications.

scholarly journals Soft System Based on Fiber Bragg Grating Sensor for Loss of Resistance Detection during Epidural Procedures: In Silico and In Vivo Assessment

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5329
Author(s):  
Francesca De Tommasi ◽  
Daniela Lo Presti ◽  
Francesca Virgili ◽  
Carlo Massaroni ◽  
Emiliano Schena ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
In Silico ◽  
Fiber Bragg Grating Sensor ◽  
Bragg Grating ◽  
Clinical Settings ◽  
Regional Technique ◽  
Loss Of Resistance ◽  
Epidural Puncture ◽  
Bragg Grating Sensor

Epidural analgesia represents a clinical common practice aiming at pain mitigation. This loco-regional technique is widely used in several applications such as labor, surgery and lower back pain. It involves the injections of anesthetics or analgesics into the epidural space (ES). The ES detection is still demanding and is usually performed by the techniques named loss of resistance (LOR). In this study, we propose a novel soft system (SS) based on one fiber Bragg grating sensor (FBG) embedded in a soft polymeric matrix for LOR detection during the epidural puncture. The SS was designed to allow instrumenting the syringe’s plunger without relevant modifications of the anesthetist’s sensations during the procedure. After the metrological characterization of the SS, we assessed the capability of this solution in detecting LOR by carrying it out in silico and in clinical settings. For both trials, results revealed the capability of the proposed solutions in detecting the LOR and then in recording the force exerted on the plunger.

Monitoring of Microorganisms Growth Process Based on Fiber Bragg Grating Biosensor

2011 ◽  
Vol 84-85 ◽  
pp. 586-589
Author(s):  
Ming Fu Zhao ◽  
De Yi Huang ◽  
Lei Zi Jiao ◽  
Xue Mei Cao ◽  
Xi Han
Keyword(s):  
Refractive Index ◽  
Fiber Bragg Grating ◽  
Nonlinear Behavior ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Refractive Index Sensitivity ◽  
Bragg Wavelength ◽  
Index Changes ◽  
Index Sensitivity ◽  
The Relationship

The low refractive index sensing principle of the fiber Bragg grating (FBG) was analyzed theoretically, the temperature compensation scheme corresponding to the theoretical model was established. A single-end etched FBG was designed and fabricated for simultaneous measurement of temperature and refractive index. The experimental results demonstrated that the Bragg wavelength shift exhibits a nonlinear behavior with the temperature and yeast refractive index changes. The temperature change to the influence of the sensor was eliminated by numerical analysis, and then the relationship between the Bragg wavelength shift and the yeast refractive index is linear, the sensor yeast refractive index sensitivity of 5.42nm/riu was obtained.

Chemical Sensors Based on Fiber Bragg Grating

2011 ◽  
Vol 84-85 ◽  
pp. 582-585 ◽  
Author(s):  
Ming Fu Zhao ◽  
De Yi Huang ◽  
Bin Zhou ◽  
Lei Zi Jiao
Keyword(s):  
Refractive Index ◽  
Fiber Bragg Grating ◽  
Chemical Sensor ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Bragg Wavelength ◽  
Chemical Substances ◽  
Fbg Sensor ◽  
Surrounding Refractive Index ◽  
The Relationship

In this paper, measurement method for the refractive index of chemical substances based on fiber Bragg grating (FBG) sensor was proposed. The relation between Bragg wavelength shift and surrounding refractive index (SRI) was analyzed theoretically and experimentally. The SRI sensitivity of the chemical sensor could be enhanced by reducing the cladding thickness of the FBG using hydrofluoric acid (HF) solution etching process. The experimental results indicated that the variation of Bragg wavelength increased as the SRI increased. In the low SRI region, the relationship between the Bragg wavelength shift and the change of the SRI was approximately linear.

scholarly journals Temperature Self-Compensated Refractive Index Sensor Based on Fiber Bragg Grating and the Ellipsoid Structure

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5211 ◽  
Author(s):  
Binbin Yan ◽  
Lei Sun ◽  
Yanhua Luo ◽  
Liwei Yang ◽  
Haifeng Qi ◽  
...  
Keyword(s):  
Refractive Index ◽  
Fiber Bragg Grating ◽  
Resonant Peak ◽  
Bragg Grating ◽  
Wavelength Shift ◽  
Refractive Index Sensor ◽  
Average Sensitivity ◽  
Surrounding Refractive Index ◽  
Index Unit ◽  
Sensing Performance

In this paper, a temperature self-compensated refractive index sensor based on fiber Bragg grating (FBG) and the ellipsoid structure is demonstrated. The ellipsoid can excite the cladding modes and recouple them into the fiber core. Two well-defined wavelength bands are observed in the reflection spectrum of the proposed sensor, i.e., the Bragg resonant peak and the cladding resonant peaks. By measuring the wavelength shift of the cladding resonant peak, the surrounding refractive index (SRI) can be determined, and the wavelength shift of the Bragg resonant peak can be used as a reliable reference to self-compensate the temperature variation (temperature sensitivity of 10.76 pm/°C). When the SRI changes from 1.3352 to 1.3722, the cladding resonant peak redshifts linearly with an average sensitivity of 352.6 pm/RIU (refractive index unit). When the SRI changes from 1.3722 to 1.4426, an exponential redshift is observed with a maximum sensitivity of 4182.2 pm/RIU. Especially, the sensing performance is not very reliant on the distance between the FBG and the ellipsoid, greatly improving the ease of the fabrication.

Investigated Solution Concentration Sensors Based on the Etched Phase Shifted Fiber Bragg Grating

2013 ◽  
Vol 380-384 ◽  
pp. 3239-3242
Author(s):  
Fu Gen Su ◽  
Xin Zhu Sang
Keyword(s):  
Refractive Index ◽  
Fiber Bragg Grating ◽  
Solution Concentration ◽  
Bragg Grating ◽  
Bragg Wavelength ◽  
Cladding Layer ◽  
The Core ◽  
Surrounding Environment ◽  
Concentration Changes ◽  
Index Changes

To remove or reduce the cladding layer thickness of fiber Bragg grating, the refractive index changes in the surrounding environment will affect the fiber Bragg grating effective refractive index of the core, resulting in changes in the Bragg wavelength. Solution concentration changes will cause changes in refractive index of the solution. A new kind of solution concentration sensor is designed with the etched phase shifted fiber Bragg grating, and concentration sensing detection with four kinds of solutions is experimentally demonstrated. With resolution concentration increasing, the phase shifted label wavelength shifts to the red, and the sensor is more sensitive in the case of higher concentration.

A High Sensitivity Pressure Sensing System with Fiber Bragg Grating Using the Transverse Strain Characteristics of a Straight Bourdon Tube

2005 ◽  
Vol 295-296 ◽  
pp. 539-544
Author(s):  
M.X. Jiao ◽  
E.G. Zhao ◽  
Y.M. Liu ◽  
R.L. Qi
Keyword(s):  
Fiber Bragg Grating ◽  
Applied Pressure ◽  
High Sensitivity ◽  
Bragg Grating ◽  
Transverse Strain ◽  
Bragg Wavelength ◽  
Pressure Sensing ◽  
Strain Characteristic ◽  
Sensing System ◽  
First Time

A high sensitivity pressure sensing system with a fiber Bragg grating (FBG) using the transverse strain characteristic of a straight bourdon tube (SBT) is presented and demonstrated for the first time to our knowledge. The transverse strain of the SBT makes the FBG tensioned. The pressure can be determined by measuring the shift of the Bragg wavelength. The experimentally obtained results indicate that the shift of the Bragg wavelength changes linearly with the applied pressure and the sensitive coefficients of pressure are approximately 6.22x10-3MPa-1. This represents a sensitivity value approximately 9.66x10-3pm/Pa. The pressure sensing system shows little hysteresis error.

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