Fabrication of Microsensor for Detection of Low-Concentration Formaldehyde Gas in Formalin-Treated Fish
01 Dec 2020-IEEE Transactions on Electron Devices (Institute of Electrical and Electronics Engineers (IEEE))-Vol. 67, Iss: 12, pp 5710-5716
TL;DR: In this paper, an ultrafast direct laser patterning technique was used to fabricate a low-cost microsensor and its application for formaldehyde detection was reported, where the patterns of microheater and interdigitated electrodes (IDEs) were realized using laser micromachining techniques by ablation of gold thin film on alumina substrate.
Abstract: Here, an ultrafast direct laser patterning technique to fabricate a low-cost microsensor and its application for formaldehyde detection are reported. The patterns of microheater and interdigitated electrodes (IDEs) were realized using laser micromachining techniques by ablation of gold thin film on alumina substrate. The thin film of gold microheater showed good stability up to 300 °C with a fast response time of 80 s and temperature coefficient of resistance (TCR) was calculated as $1.37\times 10^{-{3}}/^{\circ }\text{C}$ . Moreover, gold microheater exhibited long-term reliability under self-heating mode with a negligible resistance drift $^{-{1}}$ ) to formaldehyde even to detect sub-ppm concentrations with fast response (32 s) and recovery kinetics (72 s). Moreover, the microsensor was also used on-site rapid screening for the detection and quantification of formaldehyde concentration in formalin-treated fish sample.
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TL;DR: In this article, a highly sensitive and selective gas sensor for detecting formaldehyde is reported based on SnO2/ZnO heterospheres designed by atomic layer deposition (ALD).
Abstract: Heterostructures of metal oxide semiconductors have a great promise for chemical gas sensors due to the peculiar properties at the heterointerface. In this work, a highly sensitive and selective gas sensor for detecting formaldehyde is reported based on SnO2/ZnO heterospheres designed by atomic layer deposition (ALD). The electronic properties at the SnO2/ZnO heterointerface can be modulated by optimizing the loading of ZnO through changing ALD cycles. Gas sensing tests indicate that the ZnO ALD significantly improved the sensor properties including higher responses, faster response-recovery dynamics and better selectivity. The response of the SnO2/ZnO sensor to 1 ppm formaldehyde (Ra/Rg = 9.7) shows 4 times enhancement compared to pristine SnO2 at a working temperature of 200 °C. ZnO ALD of 10 cycles leads to the best response and recovery dynamics (12 and 24 s), and that of 15 ALD cycles results in the highest response (Ra/Rg = 38.2) to 20 ppm formaldehyde. The SnO2/ZnO sensor also registers a low detection limit of 70 ppb, which allows for reliable detection of sub-ppm formaldehyde. The remarkable sensor performances indicate the ALD surface engineering is promising for the design of new materials for reliable detection of harmful molecules.
87 citations
TL;DR: In this article, Fe2O3-sensitized SnO2 nanosheets are designed via atomic layer deposition (ALD) to realize high performance formaldehyde detection, by varying the ALD cycles, the influence of different Fe 2O3 loading on the sensing performance of SnO 2 nanOSheets is revealed.
Abstract: Metal oxide semiconductor (MOS) nanostructures have been widely explored for formaldehyde sensors. The low surface chemical and electronic properties of pure MOS, however, greatly limits the sensor functions. In this work, Fe2O3-sensitized SnO2 nanosheets are designed via atomic layer deposition (ALD) to realize high performance formaldehyde detection. By varying the ALD cycles, the influence of different Fe2O3 loading on the sensing performance of SnO2 nanosheets is revealed. It is found that Fe2O3 ALD can greatly boost the sensing performance and the SnO2 nanosheets with 20 Fe2O3 ALD cycles exhibits the best response (Ra/Rg = 4.5) and fast response and recovery dynamics (9 and 34 s) to 20 ppm formaldehyde at a relative low temperature of 220 °C. The sensor based on SnO2/Fe2O3 also displays good selectivity to formaldehyde as well as the reliable stability and low limit of detection (LOD). This work will shed some light to design efficient MOS heterostructures for detection of formaldehyde.
37 citations
01 Jan 2023-Journal of Materials Chemistry C. Materials for Optical, Magnetic and Electronic Devices
TL;DR: The significance of two-dimensional (2D) materials including graphene, and transition metal dichalcogenides has been escalating in gas sensor technology owing to detection of gases at room temperature (RT) and good performance as discussed by the authors .
Abstract: The significance of two-dimensional (2D) materials including graphene, and transition metal dichalcogenides has been escalating in gas sensor technology owing to detection of gases at room temperature (RT) and good...
1 citations
TL;DR: In this paper , a research on the evaluation of adolescent lower limb posture correction based on collaborative filtering and microsensors is carried out, which simplifies the existing human body posture monitoring model and establishes a human body model with four degrees of freedom of the lower limbs.
Abstract: Automatic monitoring of physical activity provides reliable data support for the maintenance of people's physical health and provides more scientific data for studying the relationship between physical activity and disease. In this article, a research on the evaluation of adolescent lower limb posture correction based on collaborative filtering and microsensors is carried out. Aiming at the problem that the human body posture monitoring system needs multiple nodes, this article simplifies the existing human body posture monitoring model and establishes a human body model with four degrees of freedom of the lower limbs. On this basis, the micro-sensor assembly scheme and monitoring node layout scheme for obtaining model description parameters are determined. Methods such as collaborative filtering and support vector machines are used in the process of sensor data processing and correction effect evaluation. Finally, this article uses the constructed human body posture monitoring system to carry out the recognition test of the specific posture of the human body. The experimental results show that the evaluation scheme can effectively monitor and evaluate the effect of lower limb posture correction in adolescents.
1 citations
TL;DR: In this article , density functional theory (DFT) analyzes the electronic structure of sensing materials and the adsorption energy of butyl acetate, and the effects of Ni element doping, oxygen vacancy constructions, and NiO quantum dot modifications on the modulation of the electronic structures of ZnO and on the ad-hoc energy of Butyl Acetate are investigated in detail.
References
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TL;DR: In this article, a colorimetric detection of gaseous formaldehyde was developed based on Methyl Yellow-impregnated nylon 6 nano-fiber/nets (NFN).
Abstract: A novel strategy for highly sensitive colorimetric detection of gaseous formaldehyde was developed based on Methyl Yellow-impregnated electro-spinning/netting (ESN) nylon 6 nano-fiber/nets (NFN). The sensor presented a significant reflectance intensity decreasing band at 550 nm which induce the visual color changes from yellow to red after exposure to formaldehyde and allowed for the detection of formaldehyde with a low detection limit of 50 ppb. Upon exposure to a series of volatile organic compounds (VOCs), only formaldehyde could induce a yellow-to-red color change observable by the naked eye, which clearly exhibited that Methyl Yellow-impregnated nylon 6 NFN membranes could act as highly selective and sensitive strips to detect formaldehyde with minor interference from other VOCs. Additionally, the colorimetric sensor showed good reproducibility under cyclic sensing experiments. Furthermore, the colorimetric responses were visualized quantitative by using a color-differentiation map prepared form converted RGB (red, green and blue) values. As-prepared Methyl Yellow-impregnated nylon 6 NFN sensor strips successfully combined with the visualized detection of color map and fascinating structure of NFN membranes, which indicated promising composite materials as a simple and economical alternative to replace the traditional formaldehyde sensors and facilitated the design and development of other label-free colorimetric sensors toward various analytes based on the NFN template.
82 citations
"Fabrication of Microsensor for Dete..." refers methods in this paper
...The concentration of the formaldehyde in the test chamber was calculated in ppm according to the following equation [27], [28]:...
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TL;DR: In this paper, a simple, sensitive and rapid method for the determination of formaldehyde and sulfur dioxide was developed, based on the reaction between Formaldehyde and acetylacetone solution, producing yellow 3,5diacetyl-l-1,4-dihydrolutidine.
81 citations
TL;DR: In this article, a facile coaxial electrospinning method and calcination procedure was used to synthesize core-shell α-Fe2O3@NiO nanofibers with hollow nanostructures.
Abstract: Different components and well-defined structures may cooperatively improve the performances of composite materials and enhance their applicability. In this paper, core–shell α-Fe2O3@NiO nanofibers (α-Fe2O3@NiO CSNFs) with hollow nanostructures are synthesized by a facile coaxial electrospinning method and calcination procedure. Considering the temperature-dependent solute degradation process and different influencing factors including the solvent evaporation rate and phase separation, a multistage formation mechanism has been proposed to understand the formation of the CSNF structure. The gas sensing tests indicate that the α-Fe2O3@NiO CSNFs exhibit significantly improved gas sensitivity and selectivity performances in comparison with NiO hollow nanofibers (NiO HNFs) and α-Fe2O3 nanofibers (α-Fe2O3 NFs). The response of α-Fe2O3@NiO CSNFs to 50 ppm HCHO at 240 °C is ∼12.8, which is 10- and 7.1-times higher than those of pure NiO and α-Fe2O3, respectively. The synergy between the heterojunction, core–shell hollow nanofiber structure and Fe loading into the NiO shell contribute to the enhanced response of α-Fe2O3@NiO CSNFs. Moreover, extremely fast response–recovery behavior (∼2 s and ∼9 s) has been observed at the optimal working temperature of 240 °C. The detection limit for HCHO could be lower than 1 ppm. These favorable gas sensing performances make the α-Fe2O3@NiO CSNFs promising materials for gas sensors.
74 citations
"Fabrication of Microsensor for Dete..." refers methods in this paper
...67 eV [33], sensing mechanism follows the surface-resistance controlled model....
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TL;DR: In this article, the up-to-now developed formaldehyde conductometric gas sensors are reviewed focusing on the strategies employed to enhance their response, and the effect of the grain size of conventional (thick or thin) films and diameter of the nanofibers is discussed.
73 citations
"Fabrication of Microsensor for Dete..." refers background in this paper
...Thus, the increase of the chemisorbed oxygen ions in the form of O2 , O− or O − 2 in the surface of n-type SnO2 materials leads to decrease the electron concentration in the conduction band of SnO2 materials and hence SnO2 materials show a high resistance in air due to the formation of a space–charge region [37]....
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TL;DR: In this article, a facial solution combustion synthesis is reported for preparing pristine NiO and Pt-functionalized (0.5, 1, and 2% Pt loading) NiO, which exhibit 3D hierarchical porous structure regardless the Pt-loaded amounts due to the release of gases and the loosely packed NiO particles.
Abstract: A facial solution combustion synthesis is reported for preparing pristine NiO and Pt-functionalized (0.5%, 1%, and 2% Pt loading) NiO. It was found that the obtained products exhibit 3D hierarchical porous structure regardless the Pt-loaded amounts due to the release of gases and the loosely packed NiO particles. Compared with the pristine NiO, the presence of Pt nanoparticles somehow affected the growth behavior of NiO around and embedded on these relatively big NiO nanoparticles in different size. The Pt-functionalized NiO based gas sensor showed lower operating temperature and substantially enhanced responses to formaldehyde, especially 1% Pt-loaded NiO. The 1% Pt-loaded NiO based gas sensor displayed a response value of 9.90 to 2000 ppm formaldehyde at 200 °C, whereas the pristine NiO based gas sensor only showed a response of 3.15 under the same conditions. The plausible explanation for the Pt-functionalized NiO based gas sensors to enhance the gas sensing performance is attributed to the role of Pt on the catalytic oxidation of formaldehyde and the increase of oxygen species quantity.
73 citations
"Fabrication of Microsensor for Dete..." refers background in this paper
...There are two possible oxidation reactions to happen with formaldehyde via adsorbed oxygen ions, shown as follows [39]: HCHO(ads) + 2O(ads) → CO2(gas) + H2O(gas) + 2e− (6) HCHO(ads) + O(ads) → HCOOH(gas) + e−....
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