E-Mail Alert

Add your e-mail address to receive forthcoming issues of this journal:

Journal Browser

Journal Browser

Special Issue "Recent Advances in Gas Nanosensors"

A special issue of Sensors (ISSN 1424-8220). This special issue belongs to the section "Chemical Sensors".

Deadline for manuscript submissions: 30 November 2019.

Special Issue Editors

Guest Editor
Prof. Dr. Eduard Llobet

MINOS-EMaS, Universitat Rovira i Virgili, 43007 Tarragona, Spain
Website | E-Mail
Phone: +34 977 558 502
Fax: +34 977 559 605
Interests: Gas sensors employing nanosized metal oxides and carbon nanomaterials integrated in ceramics, MEMS or flexible polymeric transducers. Nanomaterial synthesis using CVD or VPT and surface functionalization via grafting of functional groups or molecules or substitutional doping. Development of gas sensing applications in environment, security.
Guest Editor
Dr. Stella Vallejos

IMB-CNM, CSICBellaterra, Spain
Website | E-Mail
Phone: +34 935 94 77 00
Fax: +34 93 580 0267
Interests: gas sensors; nanomaterials; nanostructures; surface functionalization; micro/nanofabrication; chemical vapor deposition

Special Issue Information

Dear Colleagues,

Research for the synthesis and application of functional nanomaterials with superior gas sensing performance keeps evolving at a remarkable pace. Zero-dimensional, one-dimensional, two-dimensional  and three-dimensional material nanostructures have been reported for gas sensing. These have been synthesized via a wide spectrum of techniques, including both physical and chemical routes. The integration of these nanomaterials onto different transducer platforms, in particular MEMS (Micro-Electro-Mechanical Systems) or polymeric, in view of obtaining functional nanosensors has been the subject of many studies, in which yield, reproducibility, reliability, and long-term stability have been addressed. Different transducing schemes such as resistive, conductometric, electrochemical, resonant or optical have been considered. This Special Issue of Sensors will be dedicated to highlight the emerging technologies of gas nanosensors and their applications, and aims at presenting the latest technological and methodological developments in this interdisciplinary field. Special emphasis will be put on emerging applications for the Internet of Things (IoT), wearables and smart tags. Full papers, communications and reviews are welcome. Topics include, but are not limited to, the following:

  • Synthesis, gas sensing properties and applications of zero-dimensional nanomaterials (quantum dots, core–shell, onions-like structures, hollow spheres).
  • Synthesis, functionalization and gas sensing properties of one-dimensional metal oxide or carbon nanomaterials (nanowires, nanorods, nanotubes, nanobelts, nanoribbons, nanofibers, hierarchical nanostructures and their hybrids).
  • Synthesis, functionalization and gas sensing properties of two-dimensional materials (junctions, branched structures, nanoprisms, nanoplates, nanosheets, nanowalls, or nanodisks) based on carbon or chalcogenides (graphene, graphene oxide, reduced graphene oxide, dichalcogenides).
  • Synthesis, functionalization and gas sensing properties of Three-dimensional nanomaterials with controlled porosity in three dimensions, such as metal organic-frameworks (MOFs), molecularly imprinted polymers (MIPs) with nanoballs, nanocoils, nanocones, nanopillars or nanoflowers-like morphologies.
  • Gas sensing devices employing bare or functionalized silicon nanowires.
  • Fabrication and development of resistive, conductometric, electrochemical, resonant or optical gas nanosensors.
  • Integration of gas sensitive nanomaterials with rigid (Si-based, ceramic) or flexible (polymer, paper, textiles) transducers platforms for resistive, conductometric, electrochemical, resonant or optical gas sensing.
  • New applications of gas nanosensors (environmental, security, safety, medical).
Prof. Dr. Eduard Llobet
Dr. Stella Vallejos
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Sensors is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • gas sensors
  • nanomaterials
  • metal oxides
  • carbon-based materials
  • surface functionalization
  • nanomaterial synthesis
  • integration in transducer platforms
  • applications
  • nanofabrication

Published Papers (7 papers)

View options order results:
result details:
Displaying articles 1-7
Export citation of selected articles as:

Research

Jump to: Review

Open AccessArticle
A Sensitive Carbon Monoxide Sensor Based on Photoacoustic Spectroscopy with a 2.3 μm Mid-Infrared High-Power Laser and Enhanced Gas Absorption
Sensors 2019, 19(14), 3202; https://doi.org/10.3390/s19143202
Received: 2 July 2019 / Revised: 17 July 2019 / Accepted: 19 July 2019 / Published: 20 July 2019
PDF Full-text (10542 KB) | HTML Full-text | XML Full-text
Abstract
A photoacoustic spectroscopy (PAS)-based carbon monoxide (CO) gas sensor with a high-power laser and an enhanced gas absorption was demonstrated. The light source was a distributed feedback (DFB), continuous wave (CW) diode laser with a high output power of ~8 mW to give [...] Read more.
A photoacoustic spectroscopy (PAS)-based carbon monoxide (CO) gas sensor with a high-power laser and an enhanced gas absorption was demonstrated. The light source was a distributed feedback (DFB), continuous wave (CW) diode laser with a high output power of ~8 mW to give a strong excitation. The target gas received optical absorption enhanced two times by using a right-angle prism reflecting the laser beam. In order to reduce the noise from the background, wavelength modulation spectroscopy (WMS) and second-harmonic detection techniques were used. The modulation frequency and modulation depth were optimized theoretically and experimentally. Water vapor was added in the PAS sensor system to increase the vibrational–translational (V–T) relaxation rate of the CO molecule, which resulted in an ~8 times signal enhancement compared with the using of a dry CO/N2 gas mixture. The amplitude of the 2f signal had a 1.52-fold improvement compared to the one with only one time absorption. The experimental results showed that such a sensor had an excellent linear response to the optical power and gas concentration. At 1 s integration time, a minimum detection limit (MDL) for CO detection of 9.8 ppm was achieved. The long-term stability of the sensor system was evaluated with an Allan deviation analysis. When the integration time was 1100 s, the MDL improved to be 530 ppb. The detection performance of such a PAS-based CO sensor can be further improved when a laser with a higher output power and increasing optical absorption times is used. Full article
(This article belongs to the Special Issue Recent Advances in Gas Nanosensors)
Figures

Figure 1

Open AccessArticle
Application of an Array of Metal-Oxide Semiconductor Gas Sensors in an Assistant Personal Robot for Early Gas Leak Detection
Sensors 2019, 19(9), 1957; https://doi.org/10.3390/s19091957
Received: 14 February 2019 / Revised: 15 April 2019 / Accepted: 23 April 2019 / Published: 26 April 2019
Cited by 1 | PDF Full-text (15561 KB) | HTML Full-text | XML Full-text
Abstract
This paper proposes the application of a low-cost gas sensor array in an assistant personal robot (APR) in order to extend the capabilities of the mobile robot as an early gas leak detector for safety purposes. The gas sensor array is composed of [...] Read more.
This paper proposes the application of a low-cost gas sensor array in an assistant personal robot (APR) in order to extend the capabilities of the mobile robot as an early gas leak detector for safety purposes. The gas sensor array is composed of 16 low-cost metal-oxide (MOX) gas sensors, which are continuously in operation. The mobile robot was modified to keep the gas sensor array always switched on, even in the case of battery recharge. The gas sensor array provides 16 individual gas measurements and one output that is a cumulative summary of all measurements, used as an overall indicator of a gas concentration change. The results of preliminary experiments were used to train a partial least squares discriminant analysis (PLS-DA) classifier with air, ethanol, and acetone as output classes. Then, the mobile robot gas leak detection capabilities were experimentally evaluated in a public facility, by forcing the evaporation of (1) ethanol, (2) acetone, and (3) ethanol and acetone at different locations. The positive results obtained in different operation conditions over the course of one month confirmed the early detection capabilities of the proposed mobile system. For example, the APR was able to detect a gas leak produced inside a closed room from the external corridor due to small leakages under the door induced by the forced ventilation system of the building. Full article
(This article belongs to the Special Issue Recent Advances in Gas Nanosensors)
Figures

Figure 1

Open AccessArticle
Improved Sensitivity of α-Fe2O3 Nanoparticle-Decorated ZnO Nanowire Gas Sensor for CO
Sensors 2019, 19(8), 1903; https://doi.org/10.3390/s19081903
Received: 12 March 2019 / Revised: 5 April 2019 / Accepted: 20 April 2019 / Published: 22 April 2019
PDF Full-text (6080 KB) | HTML Full-text | XML Full-text
Abstract
A strategy for improving the sensitivity of a sensor for detecting CO and NH3 gases is presented herein. The gas sensor was fabricated from ZnO metal oxide semiconductor nanostructures grown via a vapor–liquid–solid process and decorated with α-Fe2O3 nanoparticles [...] Read more.
A strategy for improving the sensitivity of a sensor for detecting CO and NH3 gases is presented herein. The gas sensor was fabricated from ZnO metal oxide semiconductor nanostructures grown via a vapor–liquid–solid process and decorated with α-Fe2O3 nanoparticles via a sol–gel process. The response was enhanced by the formation of an α-Fe2O3/ZnO n–n heterojunction and the growth of thinner wires. ZnO nanowires were grown on indium–tin–oxide glass electrodes using Sn as a catalyst for growth instead of Au. The structure and elemental composition were investigated using field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. The gas sensing results indicate that the response value to 100 ppm CO was 18.8 at the optimum operating temperature of 300 °C. Full article
(This article belongs to the Special Issue Recent Advances in Gas Nanosensors)
Figures

Figure 1

Open AccessArticle
A Gas Sensing Channel Composited with Pristine and Oxygen Plasma-Treated Graphene
Sensors 2019, 19(3), 625; https://doi.org/10.3390/s19030625
Received: 14 December 2018 / Revised: 27 January 2019 / Accepted: 28 January 2019 / Published: 1 February 2019
PDF Full-text (2888 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Oxygen plasma treatment has been reported as an effective way of improving the response of graphene gas sensors. In this work, a gas sensor based on a composite graphene channel with a layer of pristine graphene (G) at the bottom and an oxygen [...] Read more.
Oxygen plasma treatment has been reported as an effective way of improving the response of graphene gas sensors. In this work, a gas sensor based on a composite graphene channel with a layer of pristine graphene (G) at the bottom and an oxygen plasma-treated graphene (OP-G) as a covering layer was reported. The OP-G on top provided oxygen functional groups and serves as the gas molecule grippers, while the as-grown graphene beneath serves as a fast carrier transport path. Thus, the composite channel (OP-G/G) demonstrated significantly improved response in NH3 gas sensing tests compared with the pristine G channel. Moreover, the OP-G/G channel showed faster response and recovering process than the OP-G channel. Since this kind of composite channel is fabricated from chemical vapor deposited graphene and patterned with standard photolithography, the device dimension was much smaller than a gas sensor fabricated from reduced graphene oxide and it is favorable for the integration of a large number of sensing units. Full article
(This article belongs to the Special Issue Recent Advances in Gas Nanosensors)
Figures

Figure 1

Review

Jump to: Research

Open AccessReview
Approaches to Enhancing Gas Sensing Properties: A Review
Sensors 2019, 19(7), 1495; https://doi.org/10.3390/s19071495
Received: 19 February 2019 / Revised: 13 March 2019 / Accepted: 22 March 2019 / Published: 27 March 2019
Cited by 2 | PDF Full-text (8794 KB) | HTML Full-text | XML Full-text
Abstract
A gas nanosensor is an instrument that converts the information of an unknown gas (species, concentration, etc.) into other signals (for example, an electrical signal) according to certain principles, combining detection principles, material science, and processing technology. As an effective application for detecting [...] Read more.
A gas nanosensor is an instrument that converts the information of an unknown gas (species, concentration, etc.) into other signals (for example, an electrical signal) according to certain principles, combining detection principles, material science, and processing technology. As an effective application for detecting a large number of dangerous gases, gas nanosensors have attracted extensive interest. However, their development and application are restricted because of issues such as a low response, poor selectivity, and high operation temperature, etc. To tackle these issues, various measures have been studied and will be introduced in this review, mainly including controlling the nanostructure, doping with 2D nanomaterials, decorating with noble metal nanoparticles, and forming the heterojunction. In every section, recent advances and typical research, as well mechanisms, will also be demonstrated. Full article
(This article belongs to the Special Issue Recent Advances in Gas Nanosensors)
Figures

Figure 1

Open AccessReview
Black Phosphorus-New Nanostructured Material for Humidity Sensors: Achievements and Limitations
Sensors 2019, 19(5), 1010; https://doi.org/10.3390/s19051010
Received: 25 January 2019 / Revised: 20 February 2019 / Accepted: 21 February 2019 / Published: 27 February 2019
PDF Full-text (8396 KB) | HTML Full-text | XML Full-text
Abstract
The prospects of using nanostructured black phosphorus for the development of humidity sensors are considered. It was shown that black phosphorus has a set of parameters that distinguish it from other two-dimensional (2D) materials such as graphene, silicone, and dichalcogenides. At the same [...] Read more.
The prospects of using nanostructured black phosphorus for the development of humidity sensors are considered. It was shown that black phosphorus has a set of parameters that distinguish it from other two-dimensional (2D) materials such as graphene, silicone, and dichalcogenides. At the same time, an analysis of shortcomings, limiting the use of black phosphorus as a humidity sensitive material in devices aimed for market of humidity sensors, was also conducted. Full article
(This article belongs to the Special Issue Recent Advances in Gas Nanosensors)
Figures

Figure 1

Open AccessReview
Semiconductor Metal Oxides as Chemoresistive Sensors for Detecting Volatile Organic Compounds
Sensors 2019, 19(2), 233; https://doi.org/10.3390/s19020233
Received: 29 October 2018 / Revised: 20 December 2018 / Accepted: 2 January 2019 / Published: 9 January 2019
Cited by 2 | PDF Full-text (14355 KB) | HTML Full-text | XML Full-text
Abstract
Volatile organic compounds (VOCs), which originate from painting, oil refining and vehicle exhaust emissions, are hazardous gases that have significant effects on air quality and human health. The detection of VOCs is of special importance to environmental safety. Among the various detection methods, [...] Read more.
Volatile organic compounds (VOCs), which originate from painting, oil refining and vehicle exhaust emissions, are hazardous gases that have significant effects on air quality and human health. The detection of VOCs is of special importance to environmental safety. Among the various detection methods, chemoresistive semiconductor metal oxide gas sensors are considered to be the most promising technique due to their easy production, low cost and good portability. Sensitivity is an important parameter of gas sensors and is greatly affected by the microstructure, defects, catalyst, heterojunction and humidity. By adjusting the aforementioned factors, the sensitivity of gas sensors can be improved further. In this review, attention will be focused on how to improve the sensitivity of chemoresistive gas sensors towards certain common VOCs with respect to the five factors mentioned above. Full article
(This article belongs to the Special Issue Recent Advances in Gas Nanosensors)
Figures

Figure 1

Sensors EISSN 1424-8220 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top