scholarly journals Detection of Cigarette Smoke Using a Surface-Acoustic-Wave Gas Sensor with Non-Polymer-Based Oxidized Hollow Mesoporous Carbon Nanospheres

Micromachines ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 276 ◽  
Author(s):  
Chi-Yung Cheng ◽  
Shih-Shien Huang ◽  
Chia-Min Yang ◽  
Kea-Tiong Tang ◽  
Da-Jeng Yao

The objective of this research was to develop a surface-acoustic-wave (SAW) sensor of cigarette smoke to prevent tobacco hazards and to detect cigarette smoke in real time through the adsorption of an ambient tobacco marker. The SAW sensor was coated with oxidized hollow mesoporous carbon nanospheres (O-HMC) as a sensing material of a new type, which replaced a polymer. O-HMC were fabricated using nitric acid to form carboxyl groups on carbon frameworks. The modified conditions of O-HMC were analyzed with Scanning Electron Microscopy (SEM), Fourier transform infrared spectrometry (FTIR), and X-ray diffraction (XRD). The appropriately modified O-HMC are more sensitive than polyacrylic acid and hollow mesoporous carbon nanospheres (PAA-HMC), which is proven by normalization. This increases the sensitivity of a standard tobacco marker (3-ethenylpyridine, 3-EP) from 37.8 to 51.2 Hz/ppm and prevents the drawbacks of a polymer-based sensing material. On filtering particles above 1 μm and using tar to prevent tar adhesion, the SAW sensor detects cigarette smoke with sufficient sensitivity and satisfactory repeatability. Tests, showing satisfactory selectivity to the cigarette smoke marker (3-EP) with interfering gases CH4, CO, and CO2, show that CO and CO2 have a negligible role during the detection of cigarette smoke.

2014 ◽  
Vol 28 (07) ◽  
pp. 1450056 ◽  
Author(s):  
Hua-Lin Cai ◽  
Yi Yang ◽  
Yi-Han Zhang ◽  
Chang-Jian Zhou ◽  
Cang-Ran Guo ◽  
...  

In this paper, a surface acoustic wave (SAW) biosensor with gold delay area on LiNbO 3 substrate detecting DNA sequences is proposed. By well-designed device parameters of the SAW sensor, it achieves a high performance for highly sensitive detection of target DNA. In addition, an effective biological treatment method for DNA immobilization and abundant experimental verification of the sensing effect have made it a reliable device in DNA detection. The loading mass of the probe and target DNA sequences is obtained from the frequency shifts, which are big enough in this work due to an effective biological treatment. The experimental results show that the biosensor has a high sensitivity of 1.2 pg/ml/Hz and high selectivity characteristic is also verified by the few responses of other substances. In combination with wireless transceiver, we develop a wireless receiving and processing system that can directly display the detection results.


Author(s):  
Takamitsu Iwaya ◽  
Shingo Akao ◽  
Kazushi Yamanaka ◽  
Tatsuhiro Okano ◽  
Nobuo Takeda ◽  
...  

Abstract For on-site analysis of surface materials on the moon, planets, and small bodies and for the monitoring of air quality in crewed spacecraft, we have developed a portable gas chromatograph (GC) equipped with a ball surface acoustic wave (SAW) sensor. In this study, we fabricated a 10 cm cube GC that implements the forward flush method using two metal micro-electro-mechanical-system (MEMS) columns coated with different stationary phases in microchannels fabricated by wet etching and diffusion bonding of stainless-steel plates. Using this GC, we succeeded in analyzing 10 kinds of gas within 10 min. In addition, for the application of the ball SAW GC on the ground, we also developed a palm-sized GC with a single metal capillary column and used it in the analysis of the headspace gas of sake. We showed that the ratio of peak areas differed among odorants depending on the brand and brewing process of sake.


2020 ◽  
Vol 20 (11) ◽  
pp. 7145-7150 ◽  
Author(s):  
Eunhyun Kim ◽  
Jinuk Kim ◽  
Seonggyun Ha ◽  
Changsik Song ◽  
Joo-Hyung Kim

The effects of a plasma treatment on the sensing performance of surface acoustic wave (SAW) sensors to detect chemical warfare agents (CWAs) were investigated. SAW sensors designed for an operating frequency of 250 MHz were fabricated using lift-off techniques followed by the deposition of a very thin thiourea (TU) layer as a sensing film on the sensing area of the SAW sensor. To achieve some advantages from the plasma treatment on the surface, such as cleaning, surface activation and modification, a post-plasma treatment was performed on the sensing layer and the sensing performance of the SAW sensor was measured by a comparison with the measured responses, providing different simulant gases through the gas feeding system. The sensitivity test revealed significant improvement in the sensing ability of the SAW sensor to detect DMMP, a simulant of a CWA, but with a relatively longer recovery time. The responses of other simulants at different concentrations and different simulant vapors were compared. The results showed that a plasma treatment on the sensing layer of a SAW device can improve the selectivity and sensitivity to a certain target gas or some volatile organic compounds. Therefore, a plasma treatment will be very useful for improving the selectivity and sensitivity of SAW sensors for the detection of CWAs.


Biosensors ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 4 ◽  
Author(s):  
Fabio Bahos ◽  
Arianee Sainz-Vidal ◽  
Celia Sánchez-Pérez ◽  
José Saniger ◽  
Isabel Gràcia ◽  
...  

In the present work, a novel, portable and innovative eNose composed of a surface acoustic wave (SAW) sensor array based on zeolitic imidazolate frameworks, ZIF-8 and ZIF-67 nanocrystals (pure and combined with gold nanoparticles), as sensitive layers has been tested as a non-invasive system to detect different disease markers, such as acetone, ethanol and ammonia, related to the diagnosis and control of diabetes mellitus through exhaled breath. The sensors have been prepared by spin coating, achieving continuous sensitive layers at the surface of the SAW device. Low concentrations (5 ppm, 10 ppm and 25 ppm) of the marker analytes were measured, obtaining high sensitivities, good reproducibility, short time response and fast signal recovery.


2005 ◽  
Vol 97 (11) ◽  
pp. 113505 ◽  
Author(s):  
R. Tucoulou ◽  
O. Mathon ◽  
C. Ferrero ◽  
V. Mocella ◽  
D. V. Roshchupkin ◽  
...  

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