Journal articles: 'Formaldehyde sensors'

1

Wang, Jing, Xing Ru Chen, Peng Jun Yao, Min Ji, Jin Qing Qi, and Wei Wu. "Detection of Indoor Formaldehyde Concentration Using LaSrFeO₃-Doped SnO₂ Gas Sensor." Key Engineering Materials 437 (May 2010): 349–53. http://dx.doi.org/10.4028/www.scientific.net/kem.437.349.

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Formaldehyde gas sensors with a structure of ceramic tube were fabricated by using La0.8Sr0.2FeO3-doped nanometer tin oxide. The highest response to formaldehyde appeared when the heating temperature of the La0.8Sr0.2FeO3-doped SnO2 sensor was about 370 °C. The response of the sensors to formaldehyde was measured in a gas concentration in the range of 0 - 5 ppm. The lowest formaldehyde concentration detected by 2 wt % (weight ratio) of La0.8Sr0.2FeO3-doped SnO2 gas sensor was 0.05 ppm. The response and recover times of the sensor to 0.5 ppm formaldehyde were about 120 s and 100 s, respectively. The response of the sensor to some interferent gases was tested.

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Arabi, Mohamed, Majed Alghamdi, Khalid Kabel, Ahmed Labena, Walaa S. Gado, Bhoomi Mavani, Alison J. Scott, Alexander Penlidis, Mustafa Yavuz, and Eihab Abdel-Rahman. "Detection of Volatile Organic Compounds by Using MEMS Sensors." Sensors 22, no. 11 (May 28, 2022): 4102. http://dx.doi.org/10.3390/s22114102.

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We report on the deployment of MEMS static bifurcation (DC) sensors for the detection of volatile organic compounds (VOCs): hydrogen sulfide and formaldehyde. We demonstrate a sensor that can detect as low as a few ppm of hydrogen sulfide. We also demonstrate a sensor array that can selectively detect formaldehyde in the presence of benzene, a closely related interferent. Toward that end, we investigate the sensitivity and selectivity of two detector polymers—polyaniline (PANI) and poly (2,5-dimethyl aniline) (P25DMA)—to both gases. A semiautomatic method is developed to functionalize individual sensors and sensor arrays with the detector polymers. We found that the sensor array can selectively sense 1 ppm of formaldehyde in the presence of benzene.

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He, Ying Fei, Ya Dong Jiang, Hui Ling Tai, and Guang Zhong Xie. "The Investigation of Quartz Crystal Microbalance (QCM) Formaldehyde Sensors Based on PEI-MWCNTs Composites." Advanced Materials Research 1030-1032 (September 2014): 217–22. http://dx.doi.org/10.4028/www.scientific.net/amr.1030-1032.217.

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The detection of formaldehyde is very necessary and important in both industrial and residential environments. In this paper, a novel quartz crystal microbalances (QCM) formaldehyde gas sensor has been successful fabricated based on Polyethylenimine (PEI)-multi-walled carbon nanotubes (MWCNTs) composite films by the spraying process. The morphology of films was analyzed by scanning electron microscope (SEM), and formaldehyde-sensing properties of sensors were investigated. The results showed that the prepared QCM gas sensor exhibited good response and recovery behaviors towards formaldehyde gas in the concentration range of 0-10 ppm at room temperature, which also has the superior repeatability and selectivity. Moreover, the gas-sensing mechanism of sensors was studied.

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He, Ying Fei, Ya Dong Jiang, Hui Ling Tai, and Guang Zhong Xie. "Fabrication and Formaldehyde-Sensing Property of Quartz Crystal Microbalance (QCM) Coated with PVP-MWCNTs Composites." Key Engineering Materials 645-646 (May 2015): 719–23. http://dx.doi.org/10.4028/www.scientific.net/kem.645-646.719.

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In this paper, the quartz crystal microbalance (QCM) sensors coated with polyvinyl pyrrolidone (PVP)-multiwalled carbon nanotubes (MCWNTs) nanocomposite thin films were developed by the spray process, which were used for the detection of low concentration formaldehyde at room temperature. The surface morphology and structure of films was analyzed by scanning electron microscope (SEM), UV-Vis absorption spectrometry, respectively, and the formaldehyde-sensing properties of sensors were investigated. The results showed that the prepared QCM gas sensor exhibited the linear characteristic, fast response, good reproducibility to low concentration formaldehyde within 6 ppm, and the poisoning of films was observed when the formaldehyde concentration exceeded 6ppm. Moreover, the sensitivity of the sensor could achieve up to 1Hz/ppm and had the good stability of response values.

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Park, Jae Jung, Yongsoo Kim, Chanmin Lee, Jun-Won Kook, Donghyun Kim, Jung-Hyun Kim, Ki-Seob Hwang, and Jun-Young Lee. "Colorimetric Visualization Using Polymeric Core–Shell Nanoparticles: Enhanced Sensitivity for Formaldehyde Gas Sensors." Polymers 12, no. 5 (April 25, 2020): 998. http://dx.doi.org/10.3390/polym12050998.

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Although equipment-based gas sensor systems (e.g., high-performance liquid chromatography) have been widely applied for formaldehyde gas detection, pre-treatment and expensive instrumentation are required. To overcome these disadvantages, we developed a colorimetric sensor based on polymer-based core–shell nanoparticles (PCSNPs), which are inexpensive, stable, and exhibit enhanced selectivity. Spherical and uniform poly(styrene-co-maleic anhydride) (PSMA)/polyethyleneimine (PEI) core–shell nanoparticles were prepared and then impregnated with Methyl Red (MR), Bromocresol Purple (BCP), or 4-nitrophenol (4-NP) to construct colorimetric sensors for formaldehyde gas. The intrinsic properties of these dyes were maintained when introduced into the PCSNPs. In the presence of formaldehyde, the MR, BCP, and 4-NP colorimetric sensors changed to yellow, red, and gray, respectively. The colorimetric response was maximized at a PEI/PSMA ratio of four, likely owing to the high content of amine groups. Effective formaldehyde gas detection was achieved at a relative humidity of 30% using the MR colorimetric sensor, which exhibited a large color change (92%) in 1 min. Advantageously, this stable sensor allowed sensitive and rapid naked-eye detection of low formaldehyde concentrations (0.5 ppm). Hence, this approach is promising for real-time formaldehyde gas visualization and can also be adapted to other colorimetric gas sensor systems to improve sensitivity and simplicity.

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Chobsilp, Thanattha, Thotsaphon Threrujirapapong, Visittapong Yordsri, Alongkot Treetong, Saowaluk Inpaeng, Karaked Tedsree, Paola Ayala, Thomas Pichler, Lei Shi, and Worawut Muangrat. "Highly Sensitive and Selective Formaldehyde Gas Sensors Based on Polyvinylpyrrolidone/Nitrogen-Doped Double-Walled Carbon Nanotubes." Sensors 22, no. 23 (November 30, 2022): 9329. http://dx.doi.org/10.3390/s22239329.

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A highly sensitive and selective formaldehyde sensor was successfully fabricated using hybrid materials of nitrogen-doped double-walled carbon nanotubes (N-DWCNTs) and polyvinylpyrrolidone (PVP). Double-walled carbon nanotubes (DWCNTs) and N-DWCNTs were produced by high-vacuum chemical vapor deposition using ethanol and benzylamine, respectively. Purified DWCNTs and N-DWCNTs were dropped separately onto the sensing substrate. PVP was then dropped onto pre-dropped DWCNT and N-DWCNTs (hereafter referred to as PVP/DWCNTs and PVP/N-DWCNTs, respectively). As-fabricated sensors were used to find 1,2-dichloroethane, dichloromethane, formaldehyde and toluene vapors in parts per million (ppm) at room temperature for detection measurement. The sensor response of N-DWCNTs, PVP/DWCNTs and PVP/N-DWCNTs sensors show a high response to formaldehyde but a low response to 1,2-dichloroethane, dichloromethane and toluene. Remarkably, PVP/N-DWCNTs sensors respond sensitively and selectively towards formaldehyde vapor, which is 15 times higher than when using DWCNTs sensors. This improvement could be attributed to the synergistic effect of the polymer swelling and nitrogen-sites in the N-DWCNTs. The limit of detection (LOD) of PVP/N-DWCNTs was 15 ppm, which is 34-fold higher than when using DWCNTs with a LOD of 506 ppm. This study demonstrated the high sensitivity and selectivity for formaldehyde-sensing applications of high-performance PVP/N-DWCNTs hybrid materials.

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7

Flueckiger, Jonas, Frank Ko, and Karen Cheung. "Microfabricated Formaldehyde Gas Sensors." Sensors 9, no. 11 (November 18, 2009): 9196–215. http://dx.doi.org/10.3390/s91109196.

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Merenkova, A. A., K. V. Zhuzhukin, A. N. Zyablov, and L. I. Belchinskaya. "Determination of formaldehyde in production solutions using the piezoelectric sensors." Аналитика и контроль 25, no. 2 (2021): 140–45. http://dx.doi.org/10.15826/analitika.2021.25.2.003.

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In the current work, piezoelectric sensors based on a molecular imprinted polymer (MIP) were obtained for determining the formaldehyde in the industrial solutions of a woodworking plant. The synthesis was carried out directly on the surface of the piezoelectric sensor. In the process of the two-stage thermoimidization of the obtained prepolymerization mixture, a molecular imprinted polyimide of formaldehyde was formed. For the analysis of the supra-resin part of the effluent of the Grafskaya kuhnya LLC (Voronezh) woodworking enterprise, which was obtained by the dry distillation of wood, the method of a calibration graph having a linear relationship was used; the coefficient of determination R2 = 0.97. The detection limit of the piezosensor was 0.6 ∙ 10–4 mol / dm3, the range of determined concentrations was 1.0 – 10–4 mol / dm3. The comparison of piezoelectric sensors based on the polymer without imprints and based on the polymer with imprints of formaldehyde showed high selectivity of the latter for the target molecule. The calculated imprinting factor was 28.3, the coefficient of selectivity with respect to phenol was 0.05, which indicated the selectivity of the modified sensor to formaldehyde. The verification of the correctness of the determination of formaldehyde in the model and production solutions was carried out using the "added-found" method. It was found that the MIP-based sensor was sensitive only to formaldehyde, the relative standard deviation did not exceed 2.0%. In order to assess the effect of the object matrix (formaldehyde) on the value of the resonant frequency, the standard addition method was used. It was determined that the matrix did not affect the value of the analytical signal, the relative standard deviation was 2.8%. For the re-analysis, the piezoelectric sensor was exposed to the regeneration in the oven at 50 ⁰С. The proposed method for determining the concentration of the formaldehyde using the MIP-sensor allowed controlling the content of the toxicant in the industrial solutions.

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A. Akbar, S., A. Mardhiah, N. Saidi, and D. Lelifajri. "The effect of graphite composition on polyaniline film performance for formalin gas sensor." Bulletin of the Chemical Society of Ethiopia 34, no. 3 (January 12, 2021): 597–604. http://dx.doi.org/10.4314/bcse.v34i3.14.

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The invention of formalin gas sensors based on polyaniline (PANI) has been developed which arranged by PANI|graphite composite form. The reaction between amine and formaldehyde produced a Schiff base that alters the resistance of PANI film as a function of formaldehyde concentration. The response of the sensor was measured in variations of graphite composition with 3%, 10%, and 25%. The results showed similar patterns in all concentrations of formalin. However, the sensor response at 10% and 25% graphite decreased dramatically. The formalin with concentration 400 ppm shown the response with 3% graphite was 1.62 times greater than 25%. Addition of too much graphite makes the absorption area on the PANI surface becomes less because the graphite covered it. In this case, the sensor performance was still stable and functional, but the measured resistance seems smaller because the sensor conductivity level more dominated by graphite. Therefore, composites of polyaniline and graphite can be used as sensors to detect the presence of formaldehyde gas. KEY WORDS: Formalin, Graphite, Polyaniline, Resistance, Sensors Bull. Chem. Soc. Ethiop. 2020, 34(3), 597-604. DOI: https://dx.doi.org/10.4314/bcse.v34i3.14

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10

Yuan, Zhenyu, Chang Yang, and Fanli Meng. "Strategies for Improving the Sensing Performance of Semiconductor Gas Sensors for High-Performance Formaldehyde Detection: A Review." Chemosensors 9, no. 7 (July 14, 2021): 179. http://dx.doi.org/10.3390/chemosensors9070179.

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Formaldehyde is a poisonous and harmful gas, which is ubiquitous in our daily life. Long-term exposure to formaldehyde harms human body functions; therefore, it is urgent to fabricate sensors for the real-time monitoring of formaldehyde concentrations. Metal oxide semiconductor (MOS) gas sensors is favored by researchers as a result of their low cost, simple operation and portability. In this paper, the mechanism of formaldehyde detection by gas sensors is introduced, and then the ways of ameliorating the response of gas sensors for formaldehyde detection in recent years are summarized. These methods include the control of the microstructure and morphology of sensing materials, the doping modification of matrix materials, the development of new semiconductor sensing materials, the outfield control strategy and the construction of the filter membrane. These five methods will provide a good prerequisite for the preparation of better performing formaldehyde gas sensors.

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11

Hu, Jing Ling, Ting Zhou, Yun Fei Zhang, Zhe Wang, Dong Mei Luo, and Zhong Cao. "Detection of Trace Formaldehyde Gas Based on Quartz Crystal Microbalance Sensor in Living Environment." Advanced Materials Research 233-235 (May 2011): 720–23. http://dx.doi.org/10.4028/www.scientific.net/amr.233-235.720.

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Using four types of calixarene derivatives (RCT, PCT, MRCT, TBCA) as coating materials, quartz crystal microbalance (QCM) sensors have been examined for detection of toxic formaldehyde gas indoors. The results showed that PCT was the most efficient adsorption coating material for host-guest recognition of formaldehyde molecule, when the coating mass was 43.93 μg. The PCT based QCM sensor possessed a linear response range of 109 ~ 2721 ppm formaldehyde gas. In comparison with gas chromatography method, the QCM sensor had a recovery of 97.98~104.59 % with a good reversibility, stability and reproducibility, showing that the PCT based QCM sensor can be well used for the determination of trace formaldehyde in the living environment.

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12

Chung, Po-Ren, Chun-Ta Tzeng, Ming-Tsun Ke, and Chia-Yen Lee. "Formaldehyde Gas Sensors: A Review." Sensors 13, no. 4 (April 2, 2013): 4468–84. http://dx.doi.org/10.3390/s130404468.

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13

Adamyan, Zaven, Artak Sayunts, Vladimir Aroutiounian, Emma Khachaturyan, Martin Vrnata, Přemysl Fitl, and Jan Vlček. "Nanocomposite sensors of propylene glycol, dimethylformamide and formaldehyde vapors." Journal of Sensors and Sensor Systems 7, no. 1 (February 1, 2018): 31–41. http://dx.doi.org/10.5194/jsss-7-31-2018.

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Abstract. The results of research works related to the study of thick-film multiwall carbon nanotube–tin oxide nanocomposite sensors of propylene glycol (PG), dimethylformamide (DMF) and formaldehyde (FA) vapors are presented in this paper. These sensors were derived using hydrothermal synthesis and sol–gel methods. Investigations of response–recovery characteristics in the 50–300 °C operating temperature range reveal that the optimal operating temperature for PG, DMF and FA vapor sensors, taking into account both high response and acceptable response and recovery times are about 200 and 220 °C, respectively. The dependence of the sensor response on gas concentration is linear in all cases. Minimal propylene glycol, dimethylformamide and formaldehyde gas concentrations, where the perceptible signal was noticed, were 13, 5 and 115 ppm, respectively.

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14

Zhang, Yong, Long-Zhen Xie, Chao-Xin Yuan, Chun-Lin Zhang, Su Liu, Ying-Quan Peng, Hai-Rong Li, and Miao Zhang. "A ppb-Level Formaldehyde Gas Sensor Based on Rose-Like Nickel Oxide Nanoparticles Prepared Using Electrodeposition Process." Nano 11, no. 01 (January 2016): 1650009. http://dx.doi.org/10.1142/s1793292016500090.

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In this study, rose-like nickel oxide nanoparticles (diameter of 400–500[Formula: see text]nm) were prepared on indium tin oxide (ITO) glass substrates by a simple electrodeposition in NiSO[Formula: see text]6H2O solution. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscope (TEM) were used for analysis of the NiO nanoparticles. The effects of operating temperature on the sensor response and the response versus gas concentration properties of the NiO nanorose-based sensors were investigated. We determined the operating temperature of the gas sensors to be 230[Formula: see text]C, considering the proper sensitivity and a rapid response. In addition, gas-sensing characteristics of rose-like NiO nanoparticles to formaldehyde were investigated. It was shown that the sensors exhibited good response ([Formula: see text]/[Formula: see text]) properties to formaldehyde gas at 230[Formula: see text]C, making them to be promising candidates for practical detectors to formaldehyde gas.

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Zyablov, Aleksandr, Anna Merenkova, Larisa Belchinskaya, and Konstantin Zhuzhukin. "THE USE OF PIEZOELECTRIC SYSTEMS WITH MOLECULAR PRINTS FOR FORMALDEHYDE DETERMINATION IN WASTE WATER OF WOOD PROCESSING PLANTS." Forestry Engineering Journal 11, no. 1 (March 30, 2021): 78–87. http://dx.doi.org/10.34220/issn.2222-7962/2021.1/7.

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The development of methods for controlling formaldehyde content in wastewater, ensuring high accuracy, ease of use, rapidity and efficiency is an urgent problem of the woodworking industry. This article discusses a method for determining the content of formaldehyde and its concentrations in water using piezoelectric sensor systems with molecular imprinting polymers, which make it possible to form three-dimensional complementary voids for the templates of the molecules being detected during polymerization and their subsequent removal. Piezoelectric sensor with molecular imprints of formaldehyde molecules for the express determination of its concentration in solution has been obtained. A grading graph with a linear relationship has been built. The coefficient of determination (R2) was determined to be 0.9815. Unknown concentrations of formaldehyde in solutions were found by the "added-found" method. For sensory determination of unknown concentrations in solution, the standard deviation (Sr,%) is less than 7%. Thus, it has been established that piezoelectric sensors modified with molecularly imprinted polymers allow highly accurate determination of the concentration of unknown pollutants in wastewater of woodworking enterprises. They are economically beneficial, regenerated with further deposition of a polymer with other imprints on their surface

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Spinei, Elena, Martin Tiefengraber, Moritz Müller, Manuel Gebetsberger, Alexander Cede, Luke Valin, James Szykman, et al. "Effect of polyoxymethylene (POM-H Delrin) off-gassing within the Pandora head sensor on direct-sun and multi-axis formaldehyde column measurements in 2016–2019." Atmospheric Measurement Techniques 14, no. 1 (January 28, 2021): 647–63. http://dx.doi.org/10.5194/amt-14-647-2021.

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Abstract. Analysis of formaldehyde measurements by the Pandora spectrometer systems between 2016 and 2019 suggested that there was a temperature-dependent process inside the Pandora head sensor that emitted formaldehyde. Some parts in the head sensor were manufactured from the thermal plastic polyoxymethylene homopolymer (E.I. Du Pont de Nemour & Co., USA; POM-H Delrin®) and were responsible for formaldehyde production. Laboratory analysis of the four Pandora head sensors showed that internal formaldehyde production had exponential temperature dependence with a damping coefficient of 0.0911±0.0024 ∘C−1 and the exponential function amplitude ranging from 0.0041 to 0.049 DU. No apparent dependency on the head sensor age and heating and cooling rates was detected. The total amount of formaldehyde internally generated by the POM-H Delrin components and contributing to the direct-sun measurements were estimated based on the head sensor temperature and solar zenith angle of the measurements. Measurements in winter, during colder (< 10 ∘C) days in general, and at high solar zenith angles (> 75∘) were minimally impacted. Measurements during hot days (> 28 ∘C) and small solar zenith angles had up to 1 DU (2.69×1016 molec. cm−2) contribution from POM-H Delrin parts. Multi-axis differential slant column densities were minimally impacted (<0.01 DU) due to the reference spectrum being collected within a short time period with a small difference in head sensor temperature. Three new POM-H Delrin free Pandora head sensors (manufactured in summer 2019) were evaluated for temperature-dependent attenuation across the entire spectral range (300 to 530 nm). No formaldehyde absorption or any other absorption above the instrumental noise was observed across the entire spectral range.

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17

Wang, Wei, Qinyi Zhang, Ruonan Lv, Dong Wu, and Shunping Zhang. "Enhancing Formaldehyde Selectivity of SnO2 Gas Sensors with the ZSM-5 Modified Layers." Sensors 21, no. 12 (June 8, 2021): 3947. http://dx.doi.org/10.3390/s21123947.

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High performance formaldehyde gas sensors are widely needed for indoor air quality monitoring. A modified layer of zeolite on the surface of metal oxide semiconductors results in selectivity improvement to formaldehyde as gas sensors. However, there is insufficient knowledge on how the thickness of the zeolite layer affects the gas sensing properties. In this paper, ZSM-5 zeolite films were coated on the surface of the SnO2 gas sensors by the screen printing method. The thickness of ZSM-5 zeolite films was controlled by adjusting the numbers of screen printing layers. The influence of ZSM-5 film thickness on the performance of ZSM-5/SnO2 gas sensors was studied. The results showed that the ZSM-5/SnO2 gas sensors with a thickness of 19.5 μm greatly improved the selectivity to formaldehyde, and reduced the response to ethanol, acetone and benzene at 350 °C. The mechanism of the selectivity improvement to formaldehyde of the sensors was discussed.

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S, Anil Subash, Manjunatha C, Ajit Khosla, R. Hari Krishna, and Ashoka S. "Current Progress in Materials, Device Fabrication, and Biomedical Applications of Potentiometric Sensor Devices: A Short Review." ECS Transactions 107, no. 1 (April 24, 2022): 6343–54. http://dx.doi.org/10.1149/10701.6343ecst.

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Potentiometric sensor devices are having a wide range of applications in environmental and biomedical fields. This short review aims to provide updates on recent innovations in various nanomaterials as sensing components used in potentiometric sensor devices. The review also covers the various methods and conditions used to develop these sensor nanomaterials with appropriately decorated by functional groups. Reduced graphene oxide along with traditional platinum electrodes is used to monitor algae growth in an aquatic ecosystem. Here, the addition of reduced-graphene increases the selectivity and precision of the potentiometric sensor. The review also describe the fabrication and the mechanism of sensing of carbon composite based glucose sensors, sweat sensors, and pH sensors, which are used for monitoring a human body. Sweat sensors are the ion-sensors which use carbon nanoparticles for high selectivity. Porous graphene oxide is also one of the highly used carbon nanomaterials which show high selectivity towards different types of chemicals under certain conditions. PANI/Graphene/CNT nanocomposite based potentiometric sensor is used to detect hazardous 4-aminophenol in the surrounding area. Using nanocomposite increases the selectivity and gives a high current response in the I-V graph. The granular nature of InVO4 is used in the fabrication of ammonia sensors. Formaldehyde is one of the commonly found adulterations in the food. A biosensor has been fabricated using CNTs-Fe3O4 nanocomposite to detect the formaldehyde in the foods. Finally the review summarizes the merits and limitations of various potentiometric sensors developed for different biomedical applications.

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Leidinger, M., T. Sauerwald, W. Reimringer, G. Ventura, and A. Schütze. "Selective detection of hazardous VOCs for indoor air quality applications using a virtual gas sensor array." Journal of Sensors and Sensor Systems 3, no. 2 (October 21, 2014): 253–63. http://dx.doi.org/10.5194/jsss-3-253-2014.

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Abstract. An approach for detecting hazardous volatile organic compounds (VOCs) in ppb and sub-ppb concentrations is presented. Using three types of metal oxide semiconductor (MOS) gas sensors in temperature cycled operation, formaldehyde, benzene and naphthalene in trace concentrations, reflecting threshold limit values as proposed by the WHO and European national health institutions, are successfully identified against a varying ethanol background of up to 2 ppm. For signal processing, linear discriminant analysis is applied to single sensor data and sensor fusion data. Integrated field test sensor systems for monitoring of indoor air quality (IAQ) using the same types of gas sensors were characterized using the same gas measurement setup and data processing. Performance of the systems is reduced due to gas emissions from the hardware components. These contaminations have been investigated using analytical methods. Despite the reduced sensitivity, concentrations of the target VOCs in the ppb range (100 ppb of formaldehyde; 5 ppb of benzene; 20 ppb of naphthalene) are still clearly detectable with the systems, especially when using the sensor fusion method for combining data of the different MOS sensor types.

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Korpan, Yaroslav I., Olexandr O. Soldatkin, Olga F. Sosovska, Halyna M. Klepach, Elisabeth Csöregi, Francis Vocanson, Nicole Jaffrezic-Renault, and Mykhailo V. Gonchar. "Formaldehyde-sensitive conductometric sensors based on commercial and recombinant formaldehyde dehydrogenase." Microchimica Acta 170, no. 3-4 (March 21, 2010): 337–44. http://dx.doi.org/10.1007/s00604-010-0327-z.

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Fu, Li, and Xiu Wei Fu. "Design of the Portable Detector for Formaldehyde." Advanced Materials Research 989-994 (July 2014): 615–18. http://dx.doi.org/10.4028/www.scientific.net/amr.989-994.615.

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The design of the portable formaldehyde detector based electrochemical sensors with microcontroller is introduced in the paper .In conducting the test, the formaldehyde-containing gas diffusion to the sensor internal to react with the internal electrolyte and generates a weak current signal, the current signal through the working circuit is converted to a voltage signal, the voltage signal via the signal processing circuit, and it is collected and processed by MCU after input to the A/D. the signal is communicated with operator through the buttons and LCD.

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Ren, Pengyu, Lingling Qi, Kairui You, and Qingwei Shi. "Hydrothermal Synthesis of Hierarchical SnO2 Nanostructures for Improved Formaldehyde Gas Sensing." Nanomaterials 12, no. 2 (January 11, 2022): 228. http://dx.doi.org/10.3390/nano12020228.

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The indoor environment of buildings affects people’s daily life. Indoor harmful gases include volatile organic gas and greenhouse gas. Therefore, the detection of harmful gas by gas sensors is a key method for developing green buildings. The reasonable design of SnO2-sensing materials with excellent structures is an ideal choice for gas sensors. In this study, three types of hierarchical SnO2 microspheres assembled with one-dimensional nanorods, including urchin-like microspheres (SN-1), flower-like microspheres (SN-2), and hydrangea-like microspheres (SN-3), are prepared by a simple hydrothermal method and further applied as gas-sensing materials for an indoor formaldehyde (HCHO) gas-sensing test. The SN-1 sample-based gas sensor demonstrates improved HCHO gas-sensing performance, especially demonstrating greater sensor responses and faster response/recovery speeds than SN-2- and SN-3-based gas sensors. The improved HCHO gas-sensing properties could be mainly attributed to the structural difference of smaller nanorods. These results further indicate the uniqueness of the structure of the SN-1 sample and its suitability as HCHO- sensing material.

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Lu, Tianqi, Ammar Al-Hamry, José Mauricio Rosolen, Zheng Hu, Junfeng Hao, Yuchao Wang, Anurag Adiraju, Tengfei Yu, Elaine Yoshiko Matsubara, and Olfa Kanoun. "Flexible Impedimetric Electronic Nose for High-Accurate Determination of Individual Volatile Organic Compounds by Tuning the Graphene Sensitive Properties." Chemosensors 9, no. 12 (December 15, 2021): 360. http://dx.doi.org/10.3390/chemosensors9120360.

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We investigated functionalized graphene materials to create highly sensitive sensors for volatile organic compounds (VOCs) such as formaldehyde, methanol, ethanol, acetone, and isopropanol. First, we prepared VOC-sensitive films consisting of mechanically exfoliated graphene (eG) and chemical graphene oxide (GO), which have different concentrations of structural defects. We deposited the films on silver interdigitated electrodes on Kapton substrate and submitted them to thermal treatment. Next, we measured the sensitive properties of the resulting sensors towards specific VOCs by impedance spectroscopy. We obtained the eG- and GO-based electronic nose composed of two eG films- and four GO film-based sensors with variable sensitivity to individual VOCs. The smallest relative change in impedance was 5% for the sensor based on eG film annealed at 180 °C toward 10 ppm formaldehyde, whereas the highest relative change was 257% for the sensor based on two-layers deposited GO film annealed at 200 °C toward 80 ppm ethanol. At 10 ppm VOC, the GO film-based sensors were sensitive enough to distinguish between individual VOCs, which implied excellent selectivity, as confirmed by Principle Component Analysis (PCA). According to a PCA-Support Vector Machine-based signal processing method, the electronic nose provided identification accuracy of 100% for individual VOCs. The proposed electronic nose can be used to detect multiple VOCs selectively because each sensor is sensitive to VOCs and has significant cross-selectivity to others.

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Meng, Fan Shuo, and Ai Guo Chen. "Design of a Portable Formaldehyde Meter." Advanced Materials Research 706-708 (June 2013): 708–11. http://dx.doi.org/10.4028/www.scientific.net/amr.706-708.708.

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This paper describes the design of a portable formaldehyde detector instrumentation which is based on the C8051F021 microcontroller. Using the Dart sensors for detection of formaldehyde and AD8571 precision operational amplifier for signal amplification, this meter will achieve real-time detection of formaldehyde in the air. The instrument's low power consumption, intelligent and portable features are suitable for the rapid detection of formaldehyde in indoor air.

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Güntner, Andreas T., Sebastian Abegg, Karsten Wegner, and Sotiris E. Pratsinis. "Zeolite membranes for highly selective formaldehyde sensors." Sensors and Actuators B: Chemical 257 (March 2018): 916–23. http://dx.doi.org/10.1016/j.snb.2017.11.035.

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Guo, Lanlan, Yuanyuan Wang, Hua Zeng, Yanji Feng, Xueli Yang, Saisai Zhang, Yonghao Xu, Guodong Wang, Yan Wang, and Zhanying Zhang. "Rational Design of SnO2 Hollow Microspheres Functionalized with Derivatives of Pt Loaded MOFs for Superior Formaldehyde Detection." Nanomaterials 12, no. 11 (May 31, 2022): 1881. http://dx.doi.org/10.3390/nano12111881.

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In this work, SnO2 hollow microspheres functionalized with different incorporated amounts of Pt@Co3O4 complex catalyst were innovatively designed by using an MOF template. The results show that sensor based on the optimal incorporated amount of Pt@Co3O4 not only greatly enhances the response value of SnO2 to formaldehyde (Rair/Rformaldehyde = 4240 toward 100 ppm) but also decreases the low detection limit (50 ppb), which is quite outstanding compared with other SnO2-based formaldehyde sensors. Further analysis proves that the content of oxygen vacancy and chemisorbed oxygen and the catalytic effect of ultra-small Pt play the key roles in improving the formaldehyde sensing performance. Meanwhile, this present work demonstrates that oxide semiconductors functionalized with the derivatives of MOF templated catalysts may lead to the discovery of new material systems with outstanding sensing performance.

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Kawadiya, Siddharth, Claire Welling, Sonia Grego, and Marc A. Deshusses. "Fecal Malodor Detection Using Low-Cost Electrochemical Sensors." Sensors 20, no. 10 (May 20, 2020): 2888. http://dx.doi.org/10.3390/s20102888.

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Technology innovation in sanitation is needed for the 4.2 billion people worldwide, lacking safely managed sanitation services. A major requirement for the adoption of these technologies is the management of malodor around toilet and treatment systems. There is an unmet need for a low-cost instrumented technology for detecting the onset of sanitation malodor and triggering corrective actions. This study combines sensory data with low-cost gas sensor data on malodor emanating from feces. The response of 10 commercial electrochemical gas sensors was collected alongside olfactometric measurements. Odor from fecal specimens at different relevant dilution as well as specimens with pleasant odors as a control were evaluated for a total of 64 responses. Several of the sensors responded positively to the fecal odor, with the formaldehyde, hydrogen sulfide, and ammonia sensors featuring the highest signal to noise ratio. A positive trend was observed between the sensors’ responses and the concentration of the odorant and with odor intensity, but no clear correspondence with dilution to threshold (D/T) values was found. Selected sensors were responsive both above and below the intensity values used as the cutoff for offensive odor, suggesting the possibility of using those sensors to differentiate odor offensiveness based just on the magnitude of their response. The specificity of the sensors suggested that discrimination between the selected non-fecal and fecal odors was possible. This study demonstrates that some of the evaluated sensors could be used to assemble a low-cost malodor warning system.

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Hu, Ruijin, Jing Wang, Pengpeng Chen, Yuwen Hao, Chunli Zhang, and Xiaogan Li. "Preparation of Cd-Loaded In2O3Hollow Nanofibers by Electrospinning and Improvement of Formaldehyde Sensing Performance." Journal of Nanomaterials 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/431956.

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Pure In2O3and Cd-loaded In2O3hollow and porous nanofibers with different Cd/In molar ratios (1/20, 1/10, 1/1) were synthesized by electrospinning method. X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), and transmission electron microscopy (TEM) were used to characterize the nanofibers. The porous nanofibers were composed of small grains. The average grain sizes and the diameters of Cd-loaded In2O3nanofibers increased with the increasing of Cd/In molar ratios. The formaldehyde sensing properties of the sensors based on pure In2O3and Cd-loaded In2O3nanofibers were investigated in formaldehyde concentration range of 0.5∼100 ppm. Moreover, the selectivity of those sensors was studied by testing responses to methanol, toluene, ethanol, acetone, and ammonia. The result showed that Cd-loaded In2O3nanofibers with Cd/In molar ratio of 1/10 possessed the highest response value and good selectivity at operating temperature 280°C. In addition, the formaldehyde sensing mechanism of the sensors based on Cd-loaded nanofibers was briefly analyzed.

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Guang, Qiyilan, Baoyu Huang, and Xiaogan Li. "Au-Decorated WS2 Microflakes Based Sensors for Selective Ammonia Detection at Room Temperature." Chemosensors 10, no. 1 (December 27, 2021): 9. http://dx.doi.org/10.3390/chemosensors10010009.

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Gold nanoparticles decorated WS2 microflakes (Au/WS2) have been synthesized by an in situ chemical reducing process. A chemiresistive-type sensor using as-synthesized Au/WS2 heterostructures as sensing materials shows an improved response to different concentrations of ammonia compared to pure WS2 at room temperature. As the concentrations of gold nanoparticles increased in heterostructures, response/recovery speeds of the sensors became faster although the sensitivity of the sensor was compromised compared to the sensitivity of the sensor with lower concentrations of Au. In addition, the Au/WS2-based sensor indicated excellent selectivity to formaldehyde, ethanol, benzene and acetone at room temperature. The improved performance of the sensors was attributed to the synergistic effect of electronic sensitization and chemical sensitization between WS2 and Au.

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Wang, Sun, and Lu. "Realizing the Control of Fermi Level and Gas-Sensing Selectivity over Gallium-Doped In2O3 Inverse Opal Microspheres." Proceedings 14, no. 1 (June 19, 2019): 15. http://dx.doi.org/10.3390/proceedings2019014015.

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Ying, Zhi Hua, Jia Hu, Cong Ping Wu, Yi Qing Yang, Liang Zheng, and Kai Xin Song. "Bilayer Structure Based Surface Acoustic Wave Sensor for Formaldehyde Detection." Advanced Materials Research 664 (February 2013): 986–89. http://dx.doi.org/10.4028/www.scientific.net/amr.664.986.

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This study contributes to the measurements of formaldehyde at room temperature. A bilayer structure based surface acoustic wave (SAW) sensor has been fabricated and experimentally studied. The coating materials carbon nanotubes (CNTs) and poly (4-vinylphenol) (P4VP) were deposited by a spray-painting method onto SAW sensors configured as 433.92MHz two-port resonator-based oscillators. The results display high sensitivity and entirely reversibility. The response and recovery times of the bilayer structure are very short, and the response values are obviously greater than plus of the two single layers. Some sensing mechanisms between analytes and the bilayer structure SAW sensor will be discussed preliminarily.

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Zhang, Gaoqi, Fan Zhang, Kaifang Wang, Shanyu Liu, Ying Wang, Bo Zhong, Hubin Bai, Jun Yin, Hangbin Zhang, and Lin Cong. "Enhanced Gas Sensing of Tin Dioxide Based Sensor for Indoor Formaldehyde Application." Journal of Nanoelectronics and Optoelectronics 16, no. 2 (February 1, 2021): 337–42. http://dx.doi.org/10.1166/jno.2021.2937.

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Indoor formaldehyde detection is of great important at present. Using efficient solvothermal method, nanosheet-constructed and nanorod-constructed hierarchical tin dioxide (SnO2) microspheres were successfully synthesized in this work and used for the gas sensing material for indoor formaldehyde application. The as-prepared two kinds of SnO2 gas sensing materials were applied to fabricate the gas sensors and formaldehyde gas sensing experiments were carried out. The HCHO gas sensing tests indicate that the gas response of the nanosheet-constructed SnO2 microspheres is about 1.7 times higher than that of the nanorod-constructed SnO2 microspheres. In addition, both of the two SnO2 based gas sensors show almost fast response and recovery time to HCHO gas. For the nanosheet-constructed microspheres, the response value is estimated to be 32.0 at 350 °C to 60 ppm formaldehyde gas, while the response and recovery times are 7 and 5 s, respectively. The simple and efficient preparation method and improved gas sensing properties show that the as-synthesized hierarchical SnO2 microsphere that is constructed by a large amount of nanosheets exhibits significant potential application for the indoor formaldehyde sensing.

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Ardiansyah, Adi, Sumardi Hadi Sumarlan, Sandra Malin Sutan, Dimas Firmanda Al Riza, and Hammam Hammam. "Design of Formaldehyde Detector Based on Gas Sensors." Universal Journal of Agricultural Research 10, no. 5 (October 2022): 539–47. http://dx.doi.org/10.13189/ujar.2022.100509.

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Wang, Jing, Peng Zhang, Jin-Qing Qi, and Peng-Jun Yao. "Silicon-based micro-gas sensors for detecting formaldehyde." Sensors and Actuators B: Chemical 136, no. 2 (March 2009): 399–404. http://dx.doi.org/10.1016/j.snb.2008.12.056.

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Rodner, Marius, Donatella Puglisi, Sebastian Ekeroth, Ulf Helmersson, Ivan Shtepliuk, Rositsa Yakimova, Andreas Skallberg, Kajsa Uvdal, Andreas Schütze, and Jens Eriksson. "Graphene Decorated with Iron Oxide Nanoparticles for Highly Sensitive Interaction with Volatile Organic Compounds." Sensors 19, no. 4 (February 22, 2019): 918. http://dx.doi.org/10.3390/s19040918.

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Gases, such as nitrogen dioxide, formaldehyde and benzene, are toxic even at very low concentrations. However, so far there are no low-cost sensors available with sufficiently low detection limits and desired response times, which are able to detect them in the ranges relevant for air quality control. In this work, we address both, detection of small gas amounts and fast response times, using epitaxially grown graphene decorated with iron oxide nanoparticles. This hybrid surface is used as a sensing layer to detect formaldehyde and benzene at concentrations of relevance (low parts per billion). The performance enhancement was additionally validated using density functional theory calculations to see the effect of decoration on binding energies between the gas molecules and the sensor surface. Moreover, the time constants can be drastically reduced using a derivative sensor signal readout, allowing the sensor to work at detection limits and sampling rates desired for air quality monitoring applications.

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Ocola, Leonidas E., Yale Wang, Ralu Divan, and Junhong Chen. "Multifunctional UV and Gas Sensors Based on Vertically Nanostructured Zinc Oxide: Volume Versus Surface Effect." Sensors 19, no. 9 (May 2, 2019): 2061. http://dx.doi.org/10.3390/s19092061.

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This article reports that it is possible to make multifunctional sensing devices with ZnO infiltrated polymers while the sensing interactions could occur throughout the polymer. As such, we find that infiltrated devices with SU-8 polymer can result in highly sensitive UV sensors. Mesh dielectric core devices were found to make sensitive gas sensors with a better than 5 ppm sensitivity for formaldehyde and NO2. A new type of p-n junction device is further demonstrated that is sensitive to UV illumination, thus making it an enhanced UV sensor. Sensing devices relying on volume interactions, such as light absorption, can significantly benefit from the infiltrated polymer. In contrast, devices that rely on surface interactions, such as gas sensors, do not gain performance in any significant way with or without the infiltrated polymer.

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Chen, Yu Cheng, Jian Zhong, and Lin Zhang. "Formaldehyde Gas Sensor Based on Pentacene Organic Thin-Film Transistor." Key Engineering Materials 575-576 (September 2013): 477–80. http://dx.doi.org/10.4028/www.scientific.net/kem.575-576.477.

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Formaldehyde (HCHO) gas sensors based on pentacene active layer and low cost poly (merthyl methacrylate) (PMMA) insulator were fabricated with a structure of bottom contact organic thin-film transistor (OTFT). The OTFT sensor not only presented a remarkable response characteristic in the absence and the presence of HCHO gas with different concentrations, but also exhibited a good repeatability for sensing the HCHO gas. Meanwhile, compared to the device operated in nitrogen circumstance, obvious changes in saturation drain-source current (IDS) and off-state current were observed when the device exposed to HCHO gas. Also the device performance and sensing mechanisms were discussed.

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Li, Jing, Shu-Li Yao, Sui-Jun Liu, and Yong-Qiang Chen. "Fluorescent sensors for aldehydes based on luminescent metal–organic frameworks." Dalton Transactions 50, no. 21 (2021): 7166–75. http://dx.doi.org/10.1039/d1dt00890k.

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Bogue, Robert. "Emerging applications driving innovations in gas sensing." Sensor Review 37, no. 2 (March 20, 2017): 118–26. http://dx.doi.org/10.1108/sr-11-2016-0256.

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Purpose This paper aims to show how a range of new and emerging applications are driving technological innovations in gas sensing. Design/methodology/approach Following a short introduction, this paper first considers developments relating to the needs of the military and security sectors. Wearable gas sensors, energy harvesting and self-powered gas sensors are then discussed. The role of gas sensors in mobile phones is then considered, together with details of new developments in sensors for carbon-dioxide, particulates and formaldehyde. Finally, brief conclusions are drawn. Findings This paper shows that a technologically diverse range of gas sensors is being investigated and developed in response to a number of new and emerging requirements and applications. The gas sensors respond to numerous inorganic and organic gases and vapours over a wide range of application-specific concentrations and are based on a multitude of often innovative sensing techniques, technologies and materials. Originality/value This paper provides technical details of a selection of gas sensor research activities and product developments that reflect the needs of a range of new and emerging applications.

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Linevych, Yaroslav Oleksiiovych, and Viktoriia Mykhailivna Koval. "Sensors Based on Nanoscale Silicon 1D Structures for Industrial, Environmental and Medical Monitoring." Microsystems, Electronics and Acoustics 27, no. 2 (August 21, 2022): 264376–1. http://dx.doi.org/10.20535/2523-4455.mea.264376.

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Article is devoted to the analysis of modern sensors based on silicon nanowires (SiNWs) to determine the influence of SiNWs synthesis parameters and their structural features on device characteristics. A modern trend in the development of electronic sensing devices is the use of various types of nanomaterials in order to increase sensor sensitivity and miniaturize of their size. 1D nanomaterials, namely SiNWs, have several advantages for sensor applications, such as a large surface-to-volume ratio and an increased rate of diffusion of the main charge carriers. Based on the literature analysis, an overview of modern SiNWs sensors was made. The advantages of silicon 1D structures were shown by comparison with other types of nanostructures. Also sensors were classified according to the methods of synthesis of SiNWs, sensor principle operation, kind of input value and types of applied modifiers. Silicon nanowires were most often synthesized by the method of metal-stimulated chemical etching, the advantages of which include the simplicity of implementation, low cost, and the ability to synthesize nanostructures with a high aspect ratio. The vapor-liquid-solid synthesis was also used, the advantages of which include the ability to be adapted to any technology of supplying a gas mixture with the target component and the possibility of obtaining nanowires with a diameter of 10 nm or less. According to the principle operation, the most of sensors developed on the basis of silicon nanowires are of electrical type (resistive, capacitive, electrochemical, diode or transistor type), optical sensors (fluorescent) are developed to a much lesser extent. Gas sensors (ethanol, oil vapor, formaldehyde, ammonia, nitrogen oxide, hydrogen, carbon dioxide,), liquid sensors (glucose, hydrogen peroxide, ethanol, heavy metal ions, pH), and physical values (humidity, temperature and illumination) have been developed on the basis of silicon 1D nanoscale structures. The following surface modifiers of nanowires were used to improve the performance characteristics: noble metal nanoparticles, metal-organic framework structures, carbon nanotubes, graphene, self-assembled monolayers, metal and metal oxide thin films. In particular, it was shown that the modification of the surface of the array of SiNWs with noble metals led to an increase in the sensitivity of the hydrogen sensor by 80%. Modification of formaldehyde sensor using reduced graphene oxide resulted in an improvement of sensor sensitivity by more than 2 times. The influence of SiNWs synthesis parameters on sensor performance characteristics was also determined. In particular, it was shown that increasing of SiNWs width from 20–30 nm to 500–600 nm led to an increase in the sensitivity of humidity sensor from 4.5 to 7.5%. Increasing the etching time caused the synthesis of longer nanowires, which improved the sensitivity of carbon dioxide sensors from 0.6 to 2.5%. Dependences established in this work will make it possible to develop the production technology of various types of sensors based on silicon nanowires with high sensitivity, selectivity, stability and operation speed.

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Pei, Lizhai, Fanglv Qiu, Yue Ma, Feifei Lin, Chuangang Fan, and Xianzhang Ling. "Synthesis of Polyaniline/Zn Bismuthate Nanocomposites and Sensitive Formaldehyde Sensing Performance." Current Nanoscience >15, no. 5 (July 19, 2019): 492–500. http://dx.doi.org/10.2174/1573413714666180809113244.

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Background: Formaldehyde belongs to important pollutant and is usually found in liquid environment, such as juices, beer, cleaning products and biological fluid of the human. The electrochemical sensors using glassy carbon electrode (GCE) modified with polyaniline/Zn bismuthate nanocomposites can effectively detect formaldehyde with broad linear range and good reproducibility. Methods: Polyaniline/Zn bismuthate nanocomposites were prepared by in-situ aniline polymerizing route in aqueous solution. The structure and morphologies of the nanocomposites were analyzed by X-ray diffraction (XRD) and transmission electron microscopy. The electrochemical performance for formaldehyde detection has been investigated by cyclic voltammetry (CV) method using polyaniline/ Zn bismuthate nanocomposites modified GCE. Results: XRD shows that ZnBi38O58 phase exists in the nanocomposites. Amorphous polyaniline attaches to the surface of the Zn bismuthate nanorods. The 20wt.% polyaniline/Zn bismuthate nanocomposites modified GCE shows an irreversible cyclic voltammetry (CV) peak at –0.06 V. The peak current increases sharply with increased scan rate, formaldehyde concentration and acidity. The electrochemical response dependences including the linear range, detection limit were analyzed. 20wt.% polyaniline/Zn bismuthate nanocomposites modified GCE shows low detection limit of 0.0095 µM and wide linear range of 0.00001-2 mM. The detection limit for formaldehyde decreases from 0.028 µM to 0.0075 µM with the increase in the polyaniline content from 10wt.% to 40wt.%. Conclusion: The low detection limit and wide linear range make the nanocomposites modified GCE valuable for sensor application. Polyaniline/Zn bismuthate nanocomposites are identified as the prominent electrode materials for sensitive formaldehyde detection.

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Zhang, Haihui, Nabi Ullah, Mudassar Abbas, Sumaira Naeem, Mirza Nadeem Ahmad, Shahid Hussain, Naseem Akhtar, Awais Ahmad, Muhammad Sufyan Javed, and Omar Riaz. "NiCo2O4 Nanosheets for High Performances Formaldehyde Gas Sensing Performances." Journal of Nanoelectronics and Optoelectronics 16, no. 2 (February 1, 2021): 288–92. http://dx.doi.org/10.1166/jno.2021.2950.

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The advancements in gas sensors application with maximum performances in selectivity, response, accuracy in resistance measurements and inexpensive fabrication cost has led researcher to develop and new outstand nanomaterials for environmental safety. In this study, we followed a simple hydrothermal route to synthesize ultrathin NiCo2O4 nanosheets used in gas sensing applications. The wide surface area of nanosheets provides plenty of surface area for the adsorption of HCHO gas molecules. The nanostructures are testified using XRD, XPS, SEM and TEM, respectively. The nanosheets are tested for diverse gases at assorted effective temperature ranges, and shows high response and selectivity towards formaldehyde gas. The outstanding gas-sensing properties of ultrathin NiCo2O4 nanosheets based sensor make it a potential candidate in industrial applications.

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Castro-Hurtado, I., J. Gonzalez-Chávarri, S. Morandi, J. Samà, A. Romano-Rodríguez, E. Castaño, and G. G. Mandayo. "Formaldehyde sensing mechanism of SnO2 nanowires grown on-chip by sputtering techniques." RSC Advances 6, no. 22 (2016): 18558–66. http://dx.doi.org/10.1039/c5ra26105h.

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Nguyen Van, Truong, Duc Thai Minh, Toan Tran Quoc, Chuyen Pham Hong, Thanh Dang Van, and Dung Nguyen Quoc. "Nonenzymatic formaldehyde sensors using nickel oxide based electrode fabricated by electrochemical method." Vietnam Journal of Catalysis and Adsorption 10, no. 1S (October 15, 2021): 103–7. http://dx.doi.org/10.51316/jca.2021.100.

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NiO materials were fabricated by electrochemical exfoliation combined with ultrasonic vibration to produce nano-sized particles. By electrophoresis, NiO particles dispersed in IPA solvent (isopropyl alcohol) were precipitated on the ITO substrate acting as the cathode. The morphology and structure of the materials were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). The role of electrophoresis potential, electrophoresis time on electrode formation was investigated when studying the effect on electrochemical properties of the electrode for formaldehyde in aqueous solution. As a result, with the NiO dispersion system (0.1 g NiO in 50 mL IPA), the distance between the ITO electrode (negative electrode) and the Pt plate (positive electrode) of 2 cm, the electrophoresis potential of 10 V, electrophoresis time of 3 min is optimized for fabrication of NiO/ITO electrode in formaldehyde electrochemical sensor. Sensitivity and linear range at different electrode potentials were investigated when determining the concentration of formaldehyde in water.

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Yu, Hai, Tianye Yang, Rui Zhao, Bingxin Xiao, Zhifang Li, and Mingzhe Zhang. "Fast formaldehyde gas sensing response properties of ultrathin SnO2 nanosheets." RSC Advances 5, no. 126 (2015): 104574–81. http://dx.doi.org/10.1039/c5ra22755k.

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Chen, Dazhi, and Yong J. Yuan. "Thin-Film Sensors for Detection of Formaldehyde: A Review." IEEE Sensors Journal 15, no. 12 (December 2015): 6749–60. http://dx.doi.org/10.1109/jsen.2015.2457931.

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Wang, Yu-Hsiang, Chia-Yen Lee, Che-Hsin Lin, and Lung-Ming Fu. "Enhanced sensing characteristics in MEMS-based formaldehyde gas sensors." Microsystem Technologies 14, no. 7 (November 20, 2007): 995–1000. http://dx.doi.org/10.1007/s00542-007-0460-8.

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Baez-Gaxiola, M. R., C. Fernández-Sánchez, and E. Mendoza. "Gold cluster based electrocatalytic sensors for the detection of formaldehyde." Analytical Methods 7, no. 2 (2015): 538–42. http://dx.doi.org/10.1039/c4ay02023e.

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Shi, Linqi, Jiabao Cui, Fei Zhao, Dejun Wang, Tengfeng Xie, and Yanhong Lin. "High-performance formaldehyde gas-sensors based on three dimensional center-hollow ZnO." Physical Chemistry Chemical Physics 17, no. 46 (2015): 31316–23. http://dx.doi.org/10.1039/c5cp05935f.

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Darder, Maria del Mar, Luis A. Serrano, Maximino Bedoya, and Guillermo Orellana. "3D Printing Filaments Facilitate the Development of Evanescent Wave Plastic Optical Fiber (POF) Chemosensors." Chemosensors 10, no. 2 (February 1, 2022): 61. http://dx.doi.org/10.3390/chemosensors10020061.

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One of the major difficulties in the development of evanescent wave optical fiber sensors (EWOFS) lies in the complexity of the manufacturing of the chemosensitive element, particularly when using plastic optical fibers (POFs). While these fibers are appealing waveguides thanks to their low cost, ease of connectorization and robustness, the need for removing the cladding material complicates the EWOFS fabrication. In this paper we discuss how 3D printing filaments can serve as an alternative to commercially available POF for the development of EWOFS. In the process of replacing the traditional POF, we compared the performance of two EWOFS for monitoring airborne formaldehyde. These sensitive elements were manufactured either from 1.75 mm diameter 3D printing filaments, or from a commercially available POF. After the optimization of their respective fabrication protocols, the analytical performance of the two formaldehyde EWOFS was compared in terms of sensitivity and reproducibility. In this regard, the easy-to-manufacture 3D printing filament-based waveguides provided 5-fold lower detection limits with respect to the commercial POF-based sensors. Although no statistically significant differences were found in terms of reproducibility, the simplification of the sensor manufacturing process together with the increased analytical performance for chemical sensing spur the use of 3D printing filaments for the development of new POF-based EWOFS.

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Journal articles on the topic 'Formaldehyde sensors'

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