Hydrogen Sulfide Gas Sensor Based on Copper/Graphene Oxide Composite Film-Coated Tapered Single-Mode Fibre Interferometer

2019 ◽  
Vol 74 (10) ◽  
pp. 931-936 ◽  
Author(s):  
Jiahao Yu ◽  
Xiaozhan Yang ◽  
Wenlin Feng
Keyword(s):  
Graphene Oxide ◽  
Hydrogen Sulfide ◽  
Gas Sensor ◽  
Limit Of Detection ◽  
Low Cost ◽  
Single Mode ◽  
Wavelength Shift ◽  
Sensitive Film ◽  
On Line ◽  
Cladding Mode

AbstractA hydrogen sulfide (H2S) gas sensor based on copper (Cu) nanoparticle deposited graphene oxide (GO) composite membrane with two waist-enlarged tapers is proposed. Three segments of the single-mode fibres (SMFs) are sequentially fused to obtain two waist-enlarged bitapers of Mach–Zehnder interferometer (MZI). When the light of a broadband light source transmits through the first bitaper, some light enters the fiber cladding; the lights of core mode and cladding mode are coupled at the second taper and an MZI is successfully fabricated. The copper/graphene oxide (Cu/GO) composite sensing film is coated on the surface of the second SMF, and the effective refractive index of the coating is changed when the sensitive film adsorbs the target gas. The correlation between the gas concentration and the wavelength shift is achieved and the H2S can be measured effectively. The results show that a uniform Cu/GO film is successfully coated on the surface of the fiber, and when the thickness of the sensitive film is about 1.2 μm, the sensor has a sensitivity of 4.42 pm/ppm and a good linearity and selectivity for H2S in the range of 0–60 ppm, and the limit of detection is 2.79 ppm. The response time and recovery time are approximately 31 and 48 s, respectively. The sensor has the advantages of small volume, low cost, simple structure, and easy manufacture and so on, which is suitable for on-line monitoring of H2S.

Michelson Interferometric Hydrogen Sulfide Gas Sensor Based on NH2-rGO Sensitive Film

2020 ◽  
Vol 75 (3) ◽  
pp. 241-248 ◽  
Author(s):  
Shaodian Liu ◽  
Xiaozhan Yang ◽  
Wenlin Feng ◽  
Hongliang Chen ◽  
Yu Tao ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Gas Sensor ◽  
Michelson Interferometer ◽  
High Sensitivity ◽  
Single Mode ◽  
Blue Shift ◽  
Light Signal ◽  
Sensitive Film ◽  
Recovery Times ◽  
Response And Recovery

AbstractA highly sensitive hydrogen sulfide gas sensor based on NH2-rGO-coated thin-core-fibre (TCF) Michelson interferometer (MI) is proposed and evaluated. Two sections of TCFs are alternately sandwiched between three single-mode-fibres (SMFs). A Faraday rotator mirror (FRM) is fixed to the end of the last SMF to reflect the light signal and enhance the interference. Then the structure SMF-TCF-SMF-TCF-SMF-FRM (STSTS-F) is successfully constructed. NH2-rGO, as sensing film, is coated on two TCFs and is used to detect traces of hydrogen sulfide gas. Raman spectra and XPS analysis show that NH2-rGO has been successfully synthesised. The thickness of the NH2-rGO film coated on the TCF surface is about 500 nm. By introducing 0–60 ppm hydrogen sulfide gas into the chamber, with the increase in concentration of the gas, the monitoring trough exhibits a blue shift. Our experimental results show that the sensor has good linearity (R2 = 0.98096) and selectivity for hydrogen sulfide gas. The sensitivity is 21.3 pm/ppm, and the response and recovery times are about 72 and 90 s, respectively. The sensor has the advantages of high sensitivity, high selectivity, and small size, enabling the detection of trace hydrogen sulfide in toxic gas environments.

scholarly journals Graphene Oxide and Fluorescent Aptamer Based Novel Biosensor for Detection of 25-hydroxyvitamin D3

2021 ◽  
Author(s):  
Ritika Gupta ◽  
Sunaina Kaul ◽  
Vishal Singh ◽  
Sandeep Kumar ◽  
Nitin Kumar Singhal
Keyword(s):  
Vitamin D ◽  
Graphene Oxide ◽  
Limit Of Detection ◽  
Low Cost ◽  
Resonance Energy Transfer ◽  
Resonance Energy ◽  
Detection Methods ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D ◽  
Sensitive Sensor

Abstract For maintaining the healthy metabolic status, vitamin D is a beneficial metabolite stored majorly in its pre-activated form, 25-hydroxyvitamin D3 (25(OH)D3). Due to its important role in bone strengthening, the study was planned to quantify 25(OH)D3 levels in our blood. Quantification techniques for 25(OH)D3 are costly thus requiring a need for a low cost, and sensitive detection methods. In this work, an economic, and sensitive sensor for the detection of 25(OH)D3 was developed using aptamer and graphene oxide (GO). Aptamer is an oligonucleotide, sensitive towards its target, whereas, GO with 2D nanosheets provides excellent quenching surface. Aptamer labeled with fluorescein (5’, 6-FAM) is adsorbed by π -π interaction on the GO sheets leading to quenching of the fluorescence due to Förster resonance energy transfer (FRET). However, in the presence of 25(OH)D3, a major portion of aptamer fluorescence remains unaltered, due to its association with 25(OH)D3. However, in the absence, aptamer fluorescence gets fully quenched. Fluorescence intensity quenching was monitored using fluorescence spectrophotometer and agarose gel based system. The limit of detection of 25(OH)D3 by this method was found to be 0.15 µg/mL. Therefore, this method could come up as a new sensing method in the field of vitamin D detection.

scholarly journals Development of ammonia gas sensor based on Ni-doped reduce graphene oxide

2018 ◽  
Vol 192 ◽  
pp. 02048
Author(s):  
Thanva Tubthong ◽  
Anurat Wisitsoraat ◽  
Chookiat Tansarawiput ◽  
Pakorn Opaprakasit ◽  
Paiboon Sreearunothai
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Gas Sensor ◽  
Reduce Graphene Oxide ◽  
Low Cost ◽  
Nickel Sulfate ◽  
Ammonia Removal ◽  
Resistance Change ◽  
Ammonia Gas ◽  
Reduced Graphene

The work aims to develop a simple and low cost ammonia gas sensor based on reduced graphene oxide (rGO). Reduced graphene oxide doped with nickel sulfate (NiSO4/rGO) was used as a sensing material. The sensor was fabricated by a simple drop-cast and spin-coat technique. The performance of the nickel-doped reduce graphene oxide were studied in terms of electrical changes as well as chemical interactions. It was found that after the fabricated sensor was exposed to ammonia vapour for 10 min, the average resistivity was increased to 43% from initial resistance and retained about 8% resistance change upon ammonia removal. The mechanism of the sensor reaction with the ammonia gas is also studied using Fourier Transform Infrared Spectroscopy (FTIR) and is discussed. This preliminary work may help develop the highly sensitive ammonia gas sensor.

scholarly journals Sensitive and In Situ Hemoglobin Detection Based on a Graphene Oxide Functionalized Microfiber

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2461
Author(s):  
Fang Fang ◽  
Yanpeng Li ◽  
Liuyang Yang ◽  
Liangye Li ◽  
Zhijun Yan ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Detection Limit ◽  
Light Field ◽  
Low Cost ◽  
High Sensitivity ◽  
Optical Microscope ◽  
Wavelength Shift ◽  
Compact Structure ◽  
Blood Diseases ◽  
Evanescent Light

The determination of hemoglobin (Hb) level is indispensable in the pathological study of many blood diseases. Graphene oxide (GO), with its excellent optical properties and great biocompatibility, has attracted significant attention and been widely utilized in biochemical detection. Here, we report an ultrasensitive Hb sensor based on a graphene oxide (GO)-coated microfiber. The GO was utilized as a linking layer deposited on the microfiber surface, which can provide an enhanced local evanescent light field and abundant bonding sites for Hb molecules. The optical microfiber with a compact structure and a strong evanescent light field served as the platform for biosensing. The surface morphology characterized by optical microscope, scanning electron microscope, and Raman spectroscopy offers detailed evidence for the success of GO deposition. The dynamic bonding between GO and target Hb molecules was monitored in real-time through an optical spectrum analyzer. An ultrahigh sensitivity of 6.02 nm/(mg/mL) with a detection limit of 0.17 μg/mL was achieved by tracking the resonant wavelength shift of spectra. It is important to highlight that the detection limit of GO-coated microfiber is 1–2 orders of magnitude lower than other reported fiber optic Hb sensors. Benefiting from high sensitivity, low cost, small size, and fast response, the proposed sensing microfiber coated with GO could be a competitive alternative in the diagnosis of blood diseases and a subject of further research in the medical field.

scholarly journals Incorporating N Atoms into SnO2 Nanostructure as an Approach to Enhance Gas Sensing Property for Acetone

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 445 ◽  
Author(s):  
Xiangfeng Guan ◽  
Yongjing Wang ◽  
Peihui Luo ◽  
Yunlong Yu ◽  
Dagui Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Gas Sensor ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Gas Sensing ◽  
Diffuse Reflectance Spectroscopy ◽  
Limit Of Detection ◽  
Low Cost ◽  
X Ray ◽  
Sno2 Nanostructure

The development of high-performance acetone gas sensor is of great significance for environmental protection and personal safety. SnO2 has been intensively applied in chemical sensing areas, because of its low cost, high mobility of electrons, and good chemical stability. Herein, we incorporated nitrogen atoms into the SnO2 nanostructure by simple solvothermal and subsequent calcination to improve gas sensing property for acetone. The crystallization, morphology, element composition, and microstructure of as-prepared products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Electron paramagnetic resonance (EPR), Raman spectroscopy, UV–visible diffuse reflectance spectroscopy (UV–vis DRS), and the Brunauer–Emmett–Teller (BET) method. It has been found that N-incorporating resulted in decreased crystallite size, reduced band-gap width, increased surface oxygen vacancies, enlarged surface area, and narrowed pore size distribution. When evaluated as gas sensor, nitrogen-incorporated SnO2 nanostructure exhibited excellent sensitivity for acetone gas at the optimal operating temperature of 300 °C with high sensor response (Rair/Rgas − 1 = 357) and low limit of detection (7 ppb). The nitrogen-incorporated SnO2 gas sensor shows a good selectivity to acetone in the interfering gases of benzene, toluene, ethylbenzene, hydrogen, and methane. Furthermore, the possible gas-sensing mechanism of N-incorporated SnO2 toward acetone has been carefully discussed.

Hydrogen sulfide gas sensor based on copper/graphene oxide coated multi-node thin-core fiber interferometer

2019 ◽  
Vol 58 (9) ◽  
pp. 2152 ◽  
Author(s):  
Shaodian Liu ◽  
Xiaozhan Yang ◽  
Wenlin Feng
Keyword(s):  
Graphene Oxide ◽  
Hydrogen Sulfide ◽  
Gas Sensor ◽  
Core Fiber

scholarly journals Ammonia Gas Sensor Based on Graphene Oxide-Coated Mach-Zehnder Interferometer with Hybrid Fiber Structure

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3886
Author(s):  
Xiaofeng Fan ◽  
Shuying Deng ◽  
Zhongchao Wei ◽  
Faqiang Wang ◽  
Chunhua Tan ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Relative Humidity ◽  
Gas Adsorption ◽  
Zehnder Interferometer ◽  
Wavelength Shift ◽  
Multimode Fiber ◽  
Core Diameter ◽  
Ammonia Gas ◽  
Cladding Mode ◽  
Mach Zehnder Interferometer

A graphene oxide-coated in-fiber Mach-Zehnder interferometer (MZI) formed with a multimode fiber-thin core fiber-multimode fiber (MMF-TCF-MMF) is proposed and experimentally demonstrated for ammonia gas (NH3) sensing. The MZI structure is composed of two segments of MMF of length 2 mm, with a flame-tapered TCF between them as the sensing arm. The MMFs act as mode couplers to split and recombine light owing to the core diameter mismatch with the other fibers. A tapered TCF is formed by the flame melting taper method, resulting in evanescent wave leakage. A layer of graphene oxide (GO) is applied to the tapered region of the TCF to achieve gas adsorption. The sensor operates on the principle of changing the effective refractive index of the cladding mode of a fiber through changing the conductivity of the GO coating by adsorbed NH3 molecules, which gives rise to a phase shift and shows as the resonant dip shifts in the transmission spectrum. So the concentration of the ammonia gas can be obtained by measuring the dip shift. A wavelength-shift sensitivity of 4.97 pm/ppm with a linear fit coefficient of 98.9% is achieved for ammonia gas concentrations in the range of 0 to 151 ppm. In addition, we performed a repetitive dynamic response test on the sensor by charging/releasing NH3 at concentration of 200 ppm and a relative humidity test in a relative humidity range of 35% to 70%, which demonstrates the reusability and stability of the sensor.

Enhanced NO2 sensing performance of reduced graphene oxide by in situ anchoring carbon dots

2017 ◽  
Vol 5 (27) ◽  
pp. 6862-6871 ◽  
Author(s):  
Jing Hu ◽  
Cheng Zou ◽  
Yanjie Su ◽  
Ming Li ◽  
Nantao Hu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Gas Sensor ◽  
Carbon Dots ◽  
Room Temperature ◽  
Low Cost ◽  
High Sensitivity ◽  
Reduced Graphene ◽  
Sensing Performance

A room-temperature NO2 gas sensor of high sensitivity, selectivity and stability based on a low-cost, all-carbon nanoscale heterostructure and eco-friendly 2D rGO–CD hybrids.

Sign in / Sign up

Export Citation Format

Share Document