Theoretical and Experimental Investigation on SPR Gas Sensor Based on ZnO/Polypyrrole Interface For Ammonia Sensing Applications

Abstract This work includes the exploitation of laboratory-assembled SPR technique for the application of gas sensor at room temperature. The refractive index change at the interface of ZnO/Polypyrrole with adsorption of gases (NO2 and NH3) is the basis of SPR gas sensor. The theoretical simulations were done to find out the optimum thickness of ZnO and Polypyrrole composite films for sharp SPR reflectance values. Theoretical SPR curves obtained by changing the value of thickness of Gold nanoparticles film and incident wavelength are also presented in the manuscript. Experimental studies were done to validate the theoretical studies and discussion were done about the interaction of NH3 gas with prism/Au/ZnO/Polypyrrole system. Here, ZnO/Polypyrrole multilayer structure is the sensing layer to develop highly efficient SPR based NH3 gas sensor. The outcome of these results validate the significance of SPR technique for application of interaction of surface adsorbed analytes, with the interface of dielectrics and sensing material.

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Boron-doped few-layer graphene nanosheet gas sensor for enhanced ammonia sensing at room temperature

RSC Advances ◽

10.1039/c9ra08707a ◽

2020 ◽

Vol 10 (2) ◽

pp. 1007-1014 ◽

Cited By ~ 4

Author(s):

Shubhda Srivastava ◽

Shubhendra K. Jain ◽

Govind Gupta ◽

T. D. Senguttuvan ◽

Bipin Kumar Gupta

Keyword(s):

Gas Sensor ◽

Room Temperature ◽

Gas Sensing ◽

Graphene Nanosheet ◽

Ammonia Sensing ◽

Layer Graphene ◽

Sensing Applications ◽

Boron Doped ◽

Few Layer Graphene

A boron-doped few-layer LPCVD graphene sensor is successfully designed and demonstrated for enhanced NH3 gas sensing applications.

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Metal-oxide based ammonia gas sensors: A review

Nanoscience &Nanotechnology-Asia ◽

10.2174/2210681210999200718005402 ◽

2020 ◽

Vol 10 ◽

Author(s):

Priya Gupta ◽

Savita Maurya ◽

Narendra Kumar Pandey ◽

Vernica Verma

Keyword(s):

Metal Oxide ◽

Metal Oxides ◽

Gas Sensor ◽

Gas Sensors ◽

Review Paper ◽

Gas Sensing ◽

Gas Sensitivity ◽

Ammonia Gas ◽

Ammonia Sensing ◽

Ammonia Gas Sensors

: This review paper encompasses a study of metal-oxide and their composite based gas sensors used for the detection of ammonia (NH3) gas. Metal-oxide has come into view as an encouraging choice in the gas sensor industry. This review paper focuses on the ammonia sensing principle of the metal oxides. It also includes various approaches adopted for increasing the gas sensitivity of metal-oxide sensors. Increasing the sensitivity of the ammonia gas sensor includes size effects and doping by metal or other metal oxides which will change the microstructure and morphology of the metal oxides. Different parameters that affect the performances like sensitivity, stability, and selectivity of gas sensors are discussed in this paper. Performances of the most operated metal oxides with strengths and limitations in ammonia gas sensing application are reviewed. The challenges for the development of high sensitive and selective ammonia gas sensor are also discussed.

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Optimization of a Low-Power Chemoresistive Gas Sensor: Predictive Thermal Modelling and Mechanical Failure Analysis

Sensors ◽

10.3390/s21030783 ◽

2021 ◽

Vol 21 (3) ◽

pp. 783 ◽

Cited By ~ 1

Author(s):

Andrea Gaiardo ◽

David Novel ◽

Elia Scattolo ◽

Michele Crivellari ◽

Antonino Picciotto ◽

...

Keyword(s):

Low Power ◽

Failure Analysis ◽

Gas Sensors ◽

High Performance ◽

Gas Sensing ◽

Mechanical Failure ◽

Sensing Applications ◽

Theoretical Approaches ◽

Sensing Material ◽

Silicon Bulk

The substrate plays a key role in chemoresistive gas sensors. It acts as mechanical support for the sensing material, hosts the heating element and, also, aids the sensing material in signal transduction. In recent years, a significant improvement in the substrate production process has been achieved, thanks to the advances in micro- and nanofabrication for micro-electro-mechanical system (MEMS) technologies. In addition, the use of innovative materials and smaller low-power consumption silicon microheaters led to the development of high-performance gas sensors. Various heater layouts were investigated to optimize the temperature distribution on the membrane, and a suspended membrane configuration was exploited to avoid heat loss by conduction through the silicon bulk. However, there is a lack of comprehensive studies focused on predictive models for the optimization of the thermal and mechanical properties of a microheater. In this work, three microheater layouts in three membrane sizes were developed using the microfabrication process. The performance of these devices was evaluated to predict their thermal and mechanical behaviors by using both experimental and theoretical approaches. Finally, a statistical method was employed to cross-correlate the thermal predictive model and the mechanical failure analysis, aiming at microheater design optimization for gas-sensing applications.

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Ammonia Gas Sensing Characteristic of P3HT-rGO-MWCNT Composite Films

Applied Sciences ◽

10.3390/app11156675 ◽

2021 ◽

Vol 11 (15) ◽

pp. 6675

Author(s):

Tran Si Trong Khanh ◽

Tran Quang Trung ◽

Le Thuy Thanh Giang ◽

Tran Quang Nguyen ◽

Nguyen Dinh Lam ◽

...

Keyword(s):

Response Time ◽

Gas Sensor ◽

Gas Sensing ◽

Composite Films ◽

Weight Ratio ◽

Film Surface ◽

Relative Sensitivity ◽

Ammonia Gas ◽

Casting Technique ◽

Multi Walled Carbon Nanotubes

In this work, the P3HT:rGO:MWCNTs (PGC) nanocomposite film applied to the ammonia gas sensor was successfully fabricated by a drop-casting technique. The results demonstrated that the optimum weight ratio of the PGC nanocomposite gas sensor is 20%:60%:20% as the weight ratio of P3HT:rGO:MWCNTs (called PGC-60). This weight ratio leads to the formation of nanostructured composites, causing the efficient adsorption/desorption of ammonia gas in/out of the film surface. The sensor based on PGC-60 possessed a response time of 30 s, sensitivity up to 3.6% at ammonia gas concentration of 10 ppm, and relative sensitivity of 0.031%/ppm. These results could be attributed to excellent electron transportation of rGO, the main adsorption activator to NH3 gas of P3HT, and holes move from P3HT to the cathodes, which works as charge “nano-bridges” carriers of Multi-Walled Carbon Nanotubes (MWCNTs). In general, these three components of PGC sensors have significantly contributed to the improvement of both the sensitivity and response time in the NH3 gas sensor.

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Recent Advances in ZnO-Based Carbon Monoxide Sensors: Role of Doping

Sensors ◽

10.3390/s21134425 ◽

2021 ◽

Vol 21 (13) ◽

pp. 4425

Author(s):

Ana María Pineda-Reyes ◽

María R. Herrera-Rivera ◽

Hugo Rojas-Chávez ◽

Heriberto Cruz-Martínez ◽

Dora I. Medina

Keyword(s):

Carbon Monoxide ◽

High Performance ◽

Gas Sensing ◽

Experimental Studies ◽

Electrical Performance ◽

Long Term Stability ◽

Sensing Applications ◽

Recent Advances ◽

Sensitivity And Selectivity ◽

Doped Zno

Monitoring and detecting carbon monoxide (CO) are critical because this gas is toxic and harmful to the ecosystem. In this respect, designing high-performance gas sensors for CO detection is necessary. Zinc oxide-based materials are promising for use as CO sensors, owing to their good sensing response, electrical performance, cost-effectiveness, long-term stability, low power consumption, ease of manufacturing, chemical stability, and non-toxicity. Nevertheless, further progress in gas sensing requires improving the selectivity and sensitivity, and lowering the operating temperature. Recently, different strategies have been implemented to improve the sensitivity and selectivity of ZnO to CO, highlighting the doping of ZnO. Many studies concluded that doped ZnO demonstrates better sensing properties than those of undoped ZnO in detecting CO. Therefore, in this review, we analyze and discuss, in detail, the recent advances in doped ZnO for CO sensing applications. First, experimental studies on ZnO doped with transition metals, boron group elements, and alkaline earth metals as CO sensors are comprehensively reviewed. We then focused on analyzing theoretical and combined experimental–theoretical studies. Finally, we present the conclusions and some perspectives for future investigations in the context of advancements in CO sensing using doped ZnO, which include room-temperature gas sensing.

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The Adsorption and Sensing Performances of Ir-modified MoS2 Monolayer toward SF6 Decomposition Products: A DFT Study

Nanomaterials ◽

10.3390/nano11010100 ◽

2021 ◽

Vol 11 (1) ◽

pp. 100

Author(s):

Hongcheng Liu ◽

Feipeng Wang ◽

Kelin Hu ◽

Tao Li ◽

Yuyang Yan ◽

...

Keyword(s):

Gas Sensor ◽

Density Functional ◽

Gas Adsorption ◽

Dft Method ◽

Orbital Theory ◽

Gas Sensitivity ◽

Decomposition Products ◽

Mos2 Monolayer ◽

Characteristic Decomposition ◽

Sensing Material

In this paper, the Ir-modified MoS2 monolayer is suggested as a novel gas sensor alternative for detecting the characteristic decomposition products of SF6, including H2S, SO2, and SOF2. The corresponding adsorption properties and sensing behaviors were systematically studied using the density functional theory (DFT) method. The theoretical calculation indicates that Ir modification can enhance the surface activity and improve the conductivity of the intrinsic MoS2. The physical structure formation, the density of states (DOS), deformation charge density (DCD), molecular orbital theory analysis, and work function (WF) were used to reveal the gas adsorption and sensing mechanism. These analyses demonstrated that the Ir-modified MoS2 monolayer used as sensing material displays high sensitivity to the target gases, especially for H2S gas. The gas sensitivity order and the recovery time of the sensing material to decomposition products were reasonably predicted. This contribution indicates the theoretical possibility of developing Ir-modified MoS2 as a gas sensor to detect characteristic decomposition gases of SF6.

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A Review: Carbon Nanotube-Based Piezoresistive Strain Sensors

Journal of Sensors ◽

10.1155/2012/652438 ◽

2012 ◽

Vol 2012 ◽

pp. 1-15 ◽

Cited By ~ 152

Author(s):

Waris Obitayo ◽

Tao Liu

Keyword(s):

Carbon Nanotubes ◽

Carbon Nanotube ◽

Composite Films ◽

Strain Sensors ◽

Voltage Response ◽

Strain Sensing ◽

Multiwalled Carbon ◽

Sensing Applications ◽

Mechanical Deformations ◽

Electrical Resistivities

The use of carbon nanotubes for piezoresistive strain sensors has acquired significant attention due to its unique electromechanical properties. In this comprehensive review paper, we discussed some important aspects of carbon nanotubes for strain sensing at both the nanoscale and macroscale. Carbon nanotubes undergo changes in their band structures when subjected to mechanical deformations. This phenomenon makes them applicable for strain sensing applications. This paper signifies the type of carbon nanotubes best suitable for piezoresistive strain sensors. The electrical resistivities of carbon nanotube thin film increase linearly with strain, making it an ideal material for a piezoresistive strain sensor. Carbon nanotube composite films, which are usually fabricated by mixing small amounts of single-walled or multiwalled carbon nanotubes with selected polymers, have shown promising characteristics of piezoresistive strain sensors. Studies also show that carbon nanotubes display a stable and predictable voltage response as a function of temperature.

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The Humidity Sensitive Behavior of Poly(Ethyleneimine)/Multiwall Carbon Nanotube Composite Films

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.531-532.588 ◽

2012 ◽

Vol 531-532 ◽

pp. 588-591

Author(s):

Tao Zhu ◽

Guang Zhong Xie ◽

Ya Dong Jiang ◽

Jian Liao ◽

Hui Ling Tai

Keyword(s):

Carbon Nanotube ◽

Relative Humidity ◽

Composite Films ◽

Multiwall Carbon Nanotube ◽

Sensing Material ◽

Nanotube Composites ◽

Interdigitated Microelectrode ◽

Carbon Nanotube Composite ◽

Multiwall Carbon ◽

Sensitive Behavior

In this paper, a novel humidity sensor based on polymer-carbon nanotube composites was prepared and characterized. Two different methods were adopted to fabricate the humidity-sensing film for these sensors. The surface of the films was observed by a scanning electron microscope (SEM). The sensing material made up of poly(ethyleneimine) and multiwall carbon nanotube was sprayed on the interdigitated microelectrode pairs(IDTs). The resistance between the two electrodes was measured at different relative humidity levels at 19°C. The data shows that the resistance increases with the rise of the relative humidity over the range of 5-90% RH and that, the resistance increases almost linearly in the range of 5-71% RH. The response of the sensors to NO2 and NH3 were also examined, and the results reveal that the sensor is not sensitive to both of them.

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Enhanced antibacterial activity through the controlled alignment of graphene oxide nanosheets

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1710996114 ◽

2017 ◽

Vol 114 (46) ◽

pp. E9793-E9801 ◽

Cited By ~ 126

Author(s):

Xinglin Lu ◽

Xunda Feng ◽

Jay R. Werber ◽

Chiheng Chu ◽

Ines Zucker ◽

...

Keyword(s):

Magnetic Field ◽

Antibacterial Activity ◽

Graphene Oxide ◽

Direct Electron Transfer ◽

Composite Films ◽

Experimental Studies ◽

Cross Linking ◽

Vertical Orientation ◽

Electron Transfer Mechanism ◽

Vertically Aligned

The cytotoxicity of 2D graphene-based nanomaterials (GBNs) is highly important for engineered applications and environmental health. However, the isotropic orientation of GBNs, most notably graphene oxide (GO), in previous experimental studies obscured the interpretation of cytotoxic contributions of nanosheet edges. Here, we investigate the orientation-dependent interaction of GBNs with bacteria using GO composite films. To produce the films, GO nanosheets are aligned in a magnetic field, immobilized by cross-linking of the surrounding matrix, and exposed on the surface through oxidative etching. Characterization by small-angle X-ray scattering and atomic force microscopy confirms that GO nanosheets align progressively well with increasing magnetic field strength and that the alignment is effectively preserved by cross-linking. When contacted with the model bacteriumEscherichia coli, GO nanosheets with vertical orientation exhibit enhanced antibacterial activity compared with random and horizontal orientations. Further characterization is performed to explain the enhanced antibacterial activity of the film with vertically aligned GO. Using phospholipid vesicles as a model system, we observe that GO nanosheets induce physical disruption of the lipid bilayer. Additionally, we find substantial GO-induced oxidation of glutathione, a model intracellular antioxidant, paired with limited generation of reactive oxygen species, suggesting that oxidation occurs through a direct electron-transfer mechanism. These physical and chemical mechanisms both require nanosheet penetration of the cell membrane, suggesting that the enhanced antibacterial activity of the film with vertically aligned GO stems from an increased density of edges with a preferential orientation for membrane disruption. The importance of nanosheet penetration for cytotoxicity has direct implications for the design of engineering surfaces using GBNs.

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Double Notched Long-Period Fiber Grating Characterization for CO2 Gas Sensing Applications †

Sensors ◽

10.3390/s18103206 ◽

2018 ◽

Vol 18 (10) ◽

pp. 3206 ◽

Cited By ~ 2

Author(s):

Hsiang-Chang Hsu ◽

Tso-Sheng Hsieh ◽

Tzu-Hsuan Huang ◽

Liren Tsai ◽

Chia-Chin Chiang

Keyword(s):

Gas Sensor ◽

Transmission Loss ◽

Gas Sensing ◽

Fiber Grating ◽

Co2 Gas ◽

Long Period Fiber Grating ◽

Long Period ◽

Sensing Applications ◽

Co2 Gas Sensor ◽

Period Fiber Grating

In this study, we applied a double-sided inductively coupled plasma (ICP) process to nanostructure long-period fiber grating (LPFG) in order to fabricate a double-notched LPFG (DNLPFG) sensor with a double-sided surface corrugated periodic grating. Using the sol-gel method, we also added thymol blue and ZnO to form a gas sensing layer, thus producing a DNLPFG CO2 gas sensor. The resulting sensor is the first double-sided etching sensor used to measure CO2. The experimental results showed that as the CO2 concentration increased, the transmission loss increased, and that the smaller the fiber diameter, the greater the sensitivity and the greater the change in transmission loss. When the diameter of the fiber was 32 μm (and the period was 570 μm) and the perfusion rate of CO2 gas was 15%, the maximum loss variation of up to 3.881 dB was achieved, while the sensitivity was 0.2146 dB/% and the linearity was 0.992. These results demonstrate that the DNLPG CO2 gas sensor is highly sensitive.

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