scholarly journals Nanostructured SmFeO3 Gas Sensors: Investigation of the Gas Sensing Performance Reproducibility for Colorectal Cancer Screening

Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5910
Author(s):  
Andrea Gaiardo ◽  
Giulia Zonta ◽  
Sandro Gherardi ◽  
Cesare Malagù ◽  
Barbara Fabbri ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Gas Sensors ◽  
Process Development ◽  
Gas Sensing ◽  
Diagnostic Tools ◽  
Fecal Samples ◽  
Recovery Times ◽  
Medical Diagnostic ◽  
Response And Recovery ◽  
Sensing Performance

Among the various chemoresistive gas sensing properties studied so far, the sensing response reproducibility, i.e., the capability to reproduce a device with the same sensing performance, has been poorly investigated. However, the reproducibility of the gas sensing performance is of fundamental importance for the employment of these devices in on-field applications, and to demonstrate the reliability of the process development. This sensor property became crucial for the preparation of medical diagnostic tools, in which the use of specific chemoresistive gas sensors along with a dedicated algorithm can be used for screening diseases. In this work, the reproducibility of SmFeO3 perovskite-based gas sensors has been investigated. A set of four SmFeO3 devices, obtained from the same screen-printing deposition, have been tested in laboratory with both controlled concentrations of CO and biological fecal samples. The fecal samples tested were employed in the clinical validation protocol of a prototype for non-invasive colorectal cancer prescreening. Sensors showed a high reproducibility degree, with an error lower than 2% of the response value for the test with CO and lower than 6% for fecal samples. Finally, the reproducibility of the SmFeO3 sensor response and recovery times for fecal samples was also evaluated.

Xylene-sensing of Fe2(MoO4)3 nanoplates prepared via a hydrothermal method

2017 ◽  
Vol 10 (03) ◽  
pp. 1750022 ◽  
Author(s):  
Mengying Xu ◽  
Zhidong Lin ◽  
Wenying Guo ◽  
Yuyuan Hong ◽  
Ping Fu ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Hydrothermal Process ◽  
Optimum Operating ◽  
Average Crystalline Size ◽  
Optimum Operating Temperature ◽  
Recovery Times ◽  
Response And Recovery ◽  
Simple Hydrothermal Process

Fe2(MoO4)3 nanoplates were prepared via a simple hydrothermal process. The average crystalline size of these nanoplates is 85.8[Formula: see text]nm. The sensor based on Fe2(MoO4)3 shows a high gas sensing performance to xylene. The response of Fe2(MoO4)3 sensor is 25.9–100[Formula: see text]ppm xylene at optimum operating temperature of 340[Formula: see text]C. The response and recovery times to 100[Formula: see text]ppm xylene are 4 and 10[Formula: see text]s, respectively. Furthermore, the Fe2(MoO4)3 sensor exhibits remarkable selectivity detection of xylene gas with negligible responses to toluene and benzene. Therefore, the Fe2(MoO4)3 is a promising material for the detection of xylene gas sensors.

Enhanced Gas Sensing of Tin Dioxide Based Sensor for Indoor Formaldehyde Application

2021 ◽  
Vol 16 (2) ◽  
pp. 337-342
Author(s):  
Gaoqi Zhang ◽  
Fan Zhang ◽  
Kaifang Wang ◽  
Shanyu Liu ◽  
Ying Wang ◽  
...  
Keyword(s):  
Gas Sensors ◽  
Tin Dioxide ◽  
Gas Sensing ◽  
Fast Response ◽  
Sensing Material ◽  
Gas Sensing Properties ◽  
Recovery Times ◽  
Response And Recovery ◽  
Formaldehyde Sensing ◽  
Gas Response

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.

NOx Gas Sensing Properties of Fe-Doped ZnO Nanoparticles

2020 ◽  
Vol 12 (6) ◽  
pp. 908-914 ◽  
Author(s):  
Ahmad Umar ◽  
M. Alduraibi ◽  
Omar Al-Dossary
Keyword(s):  
Gas Sensors ◽  
Zno Nanoparticles ◽  
Gas Sensing ◽  
Hydrothermal Process ◽  
Gas Sensing Properties ◽  
Recovery Times ◽  
Different Temperatures ◽  
Response And Recovery ◽  
Doped Zno ◽  
Gas Response

Herein, NOx, i.e., nitric oxide (NO) and nitrogen dioxide (NO2), gas sensors were fabricated using iron (Fe)-doped ZnO nanoparticles prepared via the facile hydrothermal process. The synthesized Fe-doped ZnO nanoparticles were analyzed through several techniques that revealed the well-crystallinity and dense growth of nanoparticles with the typical diameters of 25 ± 5 nm. The synthesized nanoparticles were utilized as a prospective material for the fabrication of NOx gas sensors operating at different temperatures, i.e., 350 °C, 400 °C, and 450 °C. The detailed sensing performances revealed that the optimum and most suitable sensing temperature for the fabricated sensors is 400 °C. In presence of 10 ppm NO gas, the fabricated sensor exhibited the highest gas response of 1.35 with a response (tresponse) and recovery (trecovery) time of 44 s and 402 s, respectively. Similarly, the fabricated NO2 gas sensor, in presence of 10 ppm gas shows the highest gas response of 1.33 with a response and recovery times of 50 s and 281 s, respectively. The presented results demonstrate that Fe-doped ZnO nanomaterials are capable to fabricate efficient NOx gas sensors.

scholarly journals Acetone Sensing and Catalytic Conversion by Pd-Loaded SnO2

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5921
Author(s):  
Pascal M. Gschwend ◽  
Florian M. Schenk ◽  
Alexander Gogos ◽  
Sotiris E. Pratsinis
Keyword(s):  
Gas Sensors ◽  
Tin Oxide ◽  
Operating Temperature ◽  
Packed Bed ◽  
Sensor Performance ◽  
Response Recovery ◽  
Recovery Times ◽  
Metal Additives ◽  
Metal Oxide Gas Sensors ◽  
Sensing Performance

Noble metal additives are widely used to improve the performance of metal oxide gas sensors, most prominently with palladium on tin oxide. Here, we photodeposit different quantities of Pd (0–3 mol%) onto nanostructured SnO2 and determine their effect on sensing acetone, a critical tracer of lipolysis by breath analysis. We focus on understanding the effect of operating temperature on acetone sensing performance (sensitivity and response/recovery times) and its relationship to catalytic oxidation of acetone through a packed bed of such Pd-loaded SnO2. The addition of Pd can either boost or deteriorate the sensing performance, depending on its loading and operating temperature. The sensor performance is optimal at Pd loadings of less than 0.2 mol% and operating temperatures of 200–262.5 °C, where acetone conversion is around 50%.

scholarly journals Gas-sensing features of nanostructured tellurium thin films

2020 ◽  
Vol 11 ◽  
pp. 1010-1018
Author(s):  
Dumitru Tsiulyanu
Keyword(s):  
Thin Films ◽  
Gas Sensing ◽  
Operating Temperature ◽  
Active Surface ◽  
Active Surface Area ◽  
Gas Sensitivity ◽  
Nanocrystalline And Amorphous ◽  
Recovery Times ◽  
Order Of Magnitude ◽  
Response And Recovery

Nanocrystalline and amorphous nanostructured tellurium (Te) thin films were grown and their gas-sensing properties were investigated at different operating temperatures with respect to scanning electron microscopy and X-ray diffraction analyses. It was shown that both types of films interacted with nitrogen dioxide, which resulted in a decrease of electrical conductivity. The gas sensitivity, as well as the response and recovery times, differed between these two nanostructured films. It is worth mentioning that these properties also depend on the operating temperature and the applied gas concentration on the films. An increase in the operating temperature decreased not only the response and recovery times but also the gas sensitivity of the nanocrystalline films. This shortcoming could be solved by using the amorphous nanostructured Te films which, even at 22 °C, exhibited higher gas sensitivity and shorter response and recovery times by more than one order of magnitude in comparison to the nanocrystalline Te films. These results were interpreted in terms of an increase in disorder (amorphization), leading to an increase in the surface chemical activity of chalcogenides, as well as an increase in the active surface area due to substrate porosity.

Gas Sensing Properties of Porous ZnO Nano-Platelet Films

2007 ◽  
Vol 1035 ◽  
Author(s):  
Amandeep Saluja ◽  
Jie Pan ◽  
Lei Kerr ◽  
Eunjung Cho ◽  
Seth Hubbard
Keyword(s):  
Gas Flow ◽  
Room Temperature ◽  
Gas Sensing ◽  
Electrode Spacing ◽  
Porous Films ◽  
Gas Sensitivity ◽  
Gas Sensing Properties ◽  
Recovery Times ◽  
Response And Recovery ◽  
Carrier Gas Flow

AbstractIn this work, various ZnO nanostructures were synthesized and a detailed study on the effect of different process parameters such as temperature, carrier gas flow, inter-electrode spacing, gas concentration and material properties on gas sensitivity was conducted. Initial ZnO nanoparticles were prepared by a simple solution chemical process and characterized by Secondary Electron Microscopy (SEM) and Brunauer, Emmet and Teller (BET) Sorptometer to demonstrate the morphology and surface area respectively. Sensitivity of nano-platelets and porous films was measured for different concentrations of the analytes (H2, CO). High response was observed at room temperature for H2 gas with sensitivities in excess 80% for 60ppm and about 55% for 80ppm of H2 gas at room temperature were observed for the nano-platelets and the porous films respectively with short response and recovery times of about 200 seconds. The sensitivity of the nano-platelets to CO gas was also measured and found to be about near 90% for 80 ppm CO at operating temperatures of 200 °C.

Emerging 2D hybrid nanomaterials: towards enhanced sensitive and selective conductometric gas sensors at room temperature

2020 ◽  
Vol 8 (38) ◽  
pp. 13108-13126
Author(s):  
Hanie Hashtroudi ◽  
Ian D. R. Mackinnon ◽  
Mahnaz Shafiei
Keyword(s):  
Gas Sensors ◽  
Room Temperature ◽  
Gas Sensing ◽  
Hybrid Nanomaterials ◽  
Sensing Performance

Gas sensing performance of conductometric devices based on 2D hybrid nanomaterials operating at room temperature.

A Formaldehyde Gas Sensor Based on Zinc Doped Lanthanum Ferrite

2013 ◽  
Vol 873 ◽  
pp. 304-310 ◽  
Author(s):  
Jin Zhang ◽  
Yu Min Zhang ◽  
Chang Yi Hu ◽  
Zhong Qi Zhu ◽  
Qing Ju Liu
Keyword(s):  
Gas Sensing ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Sensing Properties ◽  
Transmission Electron ◽  
Lanthanum Ferrite ◽  
Gas Sensing Properties ◽  
Recovery Times ◽  
Response And Recovery ◽  
Sensing Characteristics

The gas-sensing properties of zinc doped lanthanum ferrite (Zn-LaFeO3) compounds for formaldehyde were investigated in this paper. Zn-LaFeO3 powders were prepared using sol-gel method combined with microwave chemical synthesis. The powders were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. The formaldehyde gas-sensing characteristics for the sample were examined. The experimental results indicate that the sensor based on the sample Zn-LaFeO3 shows excellent gas-sensing properties to formaldehyde gas. At the optimal operating temperature of 250°C, the sensitivity of the sensor based on LaFe0.7Zn0.3O3 to 100ppm formaldehyde is 38, while to other test gases, the sensitivity is all lower than 20. The response and recovery times for the sample to formaldehyde gas are 100s and 100s, respectively.

Acetylene Sensing by ZnO/TiO2 Nanoparticles

2020 ◽  
Vol 15 (1) ◽  
pp. 41-45 ◽  
Author(s):  
Zhi-Cheng Zhong ◽  
Zhao-Jun Jing ◽  
Kui-Yuan Liu ◽  
Tong Liu
Keyword(s):  
Gas Sensors ◽  
Operating Temperature ◽  
Sol Gel ◽  
Fast Response ◽  
X Ray Diffraction ◽  
Uniform Size ◽  
X Ray ◽  
Recovery Times ◽  
Response And Recovery ◽  
Hydrothermal Methods

We adopted the sol–gel and hydrothermal methods to prepare the TiO2 nanomaterials doped with ZnO. We adopted X-ray diffraction, scanning electron microscopy, and the Brunauer–Emmett–Teller method to investigate the materials’ structures and morphologies. The results showed that the prepared TiO2 nanomaterials had uniform size and good dispersibility. Gas sensors were fabricated and their performances in acetylene sensing were assessed. The results show that the sensor prepared with the ZnO/TiO2 nanomaterial doped with 10 wt% ZnO gave fast response and recovery times for acetylene gas at different concentrations. When the operating temperature was 280 °C, the gas sensor detected 200 ppm acetylene gas with a response sensitivity of 9.9, a response time of 5 s, and a recovery time of 2 s.

Sign in / Sign up

Export Citation Format

Share Document