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Sensors and Actuators B: Chemical
Volume 145, Issue 1, 4 March 2010, Pages 488-494
A. Arenaa, N. Donatoa, G. Saittaa, A. Bonavitab, G. Rizzob and G. Nerib,,
a Dept. of Matter Physics and Electronic Engineering, Univ. of Messina, Salita Sperone 31, I-98166 Messina, Italy
b Dept. of Industrial Chemistry and Materials Engineering, Univ. of Messina, 98166 Messina, Italy
Flexible sensors for the detection of ethanol at room temperature have been developed by depositing sensitive layers consisting of ITO nanopowder dispersed into poly-diallyldimethylammonium chloride (PDDAC), on the top of interdigitated electrodes based on conductive carbon nanotubes, previously printed onto flexible glossy paper substrates. The morphology and the microstructure of the interdigitated electrodes together with organic–inorganic sensing layer have been investigated by means of SEM, XRD and FT-IR. The electrical behaviour of the developed sensors at room temperature in response to low ethanol concentrations has been discussed as object of our research. The good ethanol sensing properties exhibited at room temperature by the composite film was supposed to originate from the electrostatic interaction occurring between the positively charged PDDAC polyelectrolyte and negatively charged ITO particles.
SENSOR LETTERS
Vol.6, 1–6, 2008
G. Neri 1,*, G. Micali 1 , A. Bonavita 2 , S. Ipsale 1 , G. Rizzo 1, M. Niederberger 3 , and N. Pinna 4
1 Department of Industrial Chemistry and Materials Engineering, University of Messina,
Contrada di Dio, Vill. S. Agata, 98166 Messina, Italy
2 Department of Chemical Science and Technology, University of Rome “Tor Vergata,”
Via della Ricerca Scienti?ca 1, 00133 Rome, Italy
3 Laboratory for Multifunctional Materials, Department of Materials, ETH Zürich,
Wolfgang-Pauli-Strasse 10, CH-8093 Zürich, Switzerland
4 Department of Chemistry, CICECO, University of Aveiro, 3810-193 Aveiro, Portugal
(Received: 14 June 2007.Accepted: 31 October 2007)
The application of tungsten oxide nanowires synthesized by a simple soft-chemistry route in the presence of deferoxamine mesylate (DFOM) for ammonia gas sensing is reported. The crystalline tungsten oxide nanowires are self-assembled into bundles with typical lengths of 200 to 1000 nm and width around 20 nm. For sensing tests, tungsten oxide nanowires suspended in water were deposited onto alumina substrates by drop-coating and subsequently calcined at 500 °C in air. The sensors were tested at different temperatures to evaluate the best working conditions for ammonia gas monitoring (1–10 ppm) in terms of sensitivity, selectivity and response time. These sensors have proven to detect ammonia gas with remarkably higher sensitivity than other sensors based on tungsten oxides. The response and recovery times are fast (in the order of 2min). All in all, these features make these sensors promising candidates for healthcare applications.
Sensors and Actuators B 130 (2008) 100–104
A. Ponzonia,*, A. Deparib, M. Falasconia, E. Cominia, A. Flamminib, D. Mariolib, A. Taronib, G. Sberveglieria
a CNR-INFM Sensor Laboratory, and University of Brescia, Department of Chemistry and Physics, Via Valotti 9, 25133 Brescia, Italy
b University of Brescia, Department of Electronics for Automation and INFM, Via Branze 38, 25123 Brescia, Italy
In this work we propose a low-cost electronic nose based on a resistance to period converter readout system, suitable to handle a wide range of resistance values (from k? up to tens of G?) with high accuracy (<1%). An array composed of four metal oxide based gas sensors, with baseline resistance spreading on the above range has been used to validate the system. The electronic nose has been applied to the detection of key aromas peculiar of different stages of the bread baking process has been chosen as target application, revealing the suitability of the proposed electronic nose to distinguish these volatiles in an ordered manner re?ecting the different baking step they represent. © 2007 Elsevier B.V. All rights reserved.
Sensors and Actuators B 131 (2008) 5–9
Copyright © 2008 Elsevier B.V. All rights reserved.
Arthur L.P.S. Bailey, Anna Maria Pisanelli, Krishna C. Persaud*
School of Chemical Engineering and Analytical Science, Faraday Building, The University of Manchester, PO Box 88, Sackville Street, Manchester M60 1QD, UK
A study of conducting polymer sensors for use in monitoring the headspace of metabolites produced from super?cial wounds and burns is in progress. Gas chromatography–mass spectrometry (GC–MS) headspace analysis of the most common bacterial species found to be present in wounds has been achieved to determine the key volatile markers for sensor detection.
A preliminary study of sensor arrays using seven pure volatiles known to be produced from the bacteria studied is reported [R.A. Allardyce, V.S. Langford, A.L. Hill, D.R. Murdoch, Detection of volatile metabolites produced by bacterial growth in blood culture media by selected ion ?ow tube mass spectrometry (SIFT-MS), J. Microbiol. Methods 65 (2) (2006) 361–365; R.J. Wiggins, M. Wilks, S. Tabaqchali, Analysis by gas liquid chromatography of production of volatile fatty acids by anaerobic bacteria growth on solid medium, J. Clin. Pathol. 38 (1985) 933–936]. The sensors used were based on an existing sensor array, previously used in a smart ?re detection system [E. Scorsone, A.M. Pisanelli, K.C. Persaud, Development of an electronic nose for ?re detection, Sens. Actuators B: Chem. 116 (2006) 55–61], and a sensor array developed from the same design and con?guration has given stable results, especially towards butyric acid and ethanol.
* Corresponding author. Tel.: +44 161 3064892; fax: +44 161 3064879.
E-mail addresses: Arthur.Bailey@postgrad.manchester.ac.uk (A.L.P.S.Bailey), Krishna.persaud@manchester.ac.uk (K.C. Persaud).
G. Neri*1, A. Bonavita2, S. Ipsale1, G. Micali1, G. Rizzo1, N. Donato3
1 Dept. of Industrial Chemistry and Materials Engineering, University of Messina, C/da di Dio,
Vill. S. Agata, 98166 Messina, Italy, *e-mail – neri@ingegneria.unime.it
2 Dept. of Chemical Science and Technologies, University of Rome “Tor Vergata”
00133 Rome, Italy
3 Dept. of Matter Physics and Advanced Physical Technologies, University of Messina, Italy
ISIE 2007 – IEEE International Symposium on Industrial Electronics, June 4-7, 2007, Vigo, Spain.
Resistive metal-oxide semiconductor (MOS) sensors have been tested in the monitoring of carbonyl sulphide (COS), a biomarker for acute rejection (AR) in lung transplanted patients. COS concentration in the breath of these patients (about 0.5 ppm) is in fact more higher than that found in healthy peoples, making possible the real time diagnosis of this pathology by breath analysis. In2O3-based MOS resistive sensors have been therefore tested at different temperatures and COS concentrations in order to optimize the sensor response and response/recovery time. The ultimate aim of this work is to develop a simple and cost-effective breath test for the acute rejection in lung transplanted patients.
G. Neri, G. Micali, A. Bonavita, S. Ipsale, G. Rizzo, M. Niederberger, N. Pinna
E-MRS 2007 Spring Meeting will be held in Strasbourg (France), from May 28 to June 1, 2007
Breath analysis of ammonia gas by means of MOS sensors has promising applications in healthcare, allowing for example the easy diagnosis of uremia or determination of dialysis time. This is possible because of the correlation between exhaled ammonia and nitrogen compounds (i.e. urea and creatinine) in the blood. However, ammonia concentrations to be detected are in the range 100 ppb-2 ppm and highly sensitive and selective sensors are needed. Here we report on the application of WO3 nanofibers for reversible ammonia gas sensing. Nanotubes/fibers can contribute to the development of novel gas sensors from these materials with high performances as consequence of their high surface-to-volume ratio. We report a simple soft-chemistry route to crystalline tungsten oxide nanowires self-assembled into bundles, starting from tungsten isopropoxide in benzyl alcohol to provide a versatile reaction system for the nonaqueous preparation of these nanowires. Nanowires obtained are crystalline with a length ranging typically from 300 to 1000 nm and width between 20 and 100 nm. For the gas-sensing tests, a suspension of the tungsten oxide nanowires in ethanol was deposited onto alumina substrates by drop-coating and subsequently calcined at 500 °C in air. The sensors were tested at different temperature to evaluate the best working conditions for ammonia gas monitoring (1-10 ppm) in term of sensitivity, stability and response time. WO3-nanofiber-based sensors have proven capable of detecting ammonia gas with high sensitivity, remarkably higher than that obtained on previous sensors based on bulk WO3 materials. The response time is rapid (a few seconds) and the recovery time is also fast (in the order of 2–3 min), making the sensor promising candidate for healthcare applications.
Emilia Bramantia, Lucia D’Ulivoa, Cristina Lomontea, b, Massimo Onora, Roberto Zambonic, Giorgio Raspia and Alessandro D’Ulivoa
aItalian National Research Council, CNR-Istituto per i Processi Chimico-Fisici, Laboratory of Instrumental Analytical Chemistry, Via G. Moruzzi 1, 56124 Pisa, Italy
bAmbiente s.c.r.l., Via Frassina 21, 54033, Carrrara, Massa, Italy
cDepartment of Chemistry and Industrial Chemistry, University of Pisa, Via Risorgimento 35, 56126 Pisa, Italy
Received 29 April 2006; revised 4 July 2006; accepted 4 July 2006. Available online 8 July 2006.
Analytica Chimica Acta
Volume 579, Issue 1, 2 October 2006, Pages 38-46
Copyright © 2006 Elsevier B.V. All rights reserved.
A new procedure is proposed for the sampling and storage of hydrogen sulphide (H2S) and volatile thiols (methanethiol or methyl mercaptan, ethanethiol and propanethiol) for their determination by liquid chromatography. The sampling procedure is based on the trapping/pre-concentration of the analytes in alkaline aqueous solution containing an organic mercurial probe p-hydroxymercurybenzoate, HO–Hg–C6H4–COO− (PHMB), where they are derivatized to stable PHMB complexes based on mercury–sulfur covalent bonds. PHMB complexes are separated on a C18 reverse phase column, allowing their determination by liquid chromatography coupled with sequential non-selective UV–vis (DAD) and mercury specific (chemical vapor generation atomic fluorescence spectrometry, CVGAFS) on-line detectors. PHMB complexes, S(PHMB)2CH3S-PHMB, C2H5S-PHMB and C3H7S-PHMB, are stable alt least for 12 h at room temperature and for 3 months if stored frozen (−20 °C).
The best analytical figures of merits in the optimized conditions were obtained by CVGAFS detection, with detection limits (LODc) of 9.7 μg L−1 for H2S, 13.7 μg L−1 for CH3SH, 17.7 μg L−1 for C2H5SH and 21.7 μg L−1 for C3H7SH in the trapping solution in form of RS-PHMB complexes, the relative standard deviation (R.S.D.) ranging between 1.0 and 1.5%, and a linear dynamic range (LDR) between 10 and 9700 μg L−1. Conventional UV absorbance detectors tuned at 254 nm can be employed as well with comparable R.S.D. and LDR, but with LODc one order of magnitude higher than AFS detector and lower specificity. The sampling procedure followed by LC–DAD-CVGAFS analysis has been validated, as example, for H2S determination by a certified gas permeation tube as a source of 3.071 ± 0.154 μg min−1 of H2S, giving a recovery of 99.8 ± 7% and it has been applied to the determination of sulfur compounds in real gas samples (biogas and the air of a plant for fractional distillation of crude oil).
Neri, G.; Bonavita, A.; Rizzo, G.; Micali, G.; Donato, N.; Ipsale, S.
Sensors Journal, IEEE
Volume: 6 Issue: 5 Oct. 2006
Page(s): 1120- 1125
Digital Object Identifier 10.1109/JSEN.2006.881347
Ethanol permeation tubes have been proposed for a possible use in temperature-compensated gas-sensor calibrators. Two commercial tubes with a different geometric configuration of the polymeric membrane (wafer- and EL-type) have been tested. First, their permeation characteristics have been evaluated and, subsequently, their performances tested in an apparatus simulating programmed temperature cycles. Both tubes have shown a linear permeation rate in the range of temperature investigated and a low permeation temperature coefficient, with the EL-type tube showing also a very fast response to temperature variation. The integration of this latter tube with a flow-compensation controller has lead to the realization of a temperature-compensated calibrator device, allowing to maintain the ethanol concentration constant at the calibrator outlet by simply modulating the carrier flow through the permeation tube to compensate the temperature fluctuation. Results obtained in the generation of calibrated gas-phase ethanol concentrations, in the range from 1 to 500 ppm, suggest a promising use of these temperature-compensated permeation tubes as calibrators in portable gas-sensor devices.
Neri, G. Bonavita, A. Rizzo, G. Galvagno, S. Donato, N. Ipsale, S.
Dept. of Ind. Chem. & Mater. Eng., Messina Univ., Italy;
This paper appears in: Sensors, 2004. Proceedings of IEEE
Publication Date: 24-27 Oct. 2004
On page(s): 734- 737 vol.2
ISSN:
ISBN: 0-7803-8692-2
INSPEC Accession Number: 8478183
Digital Object Identifier: 10.1109/ICSENS.2004.1426272
Posted online: 2005-05-09 09:48:06.0
A new temperature-independent set-up for gas sensors calibration making use of permeation tubes is proposed. The control of the output gas-phase concentration from the calibrator was made modulating the carrier flow through the permeation tube as a function of the temperature and dynamic of the tube by an entirely computer-controlled system. The study and results related to generation of calibrated gas-phase ethanol concentrations (from 1 to 500 ppm) and the calibration of a MOS (metal oxide semiconductor) gas sensor by this apparatus have been reported.
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