| 1. |
- Comini, Elisabetta, et al.
(författare)
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Effects of Ta/Nb-doping on titania-based thin films for gas-sensing
- 2005
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier BV. - 0925-4005 .- 1873-3077. ; 108:1-2 SPEC. ISS., s. 21-28
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Tidskriftsartikel (refereegranskat)abstract
- Thin films of titania with the addition of niobium and tantalum have been achieved by reactive sputtering process. Structural and morphological studies have been carried out by means of XRD, RBS, TEM and AFM in order to correlate the microstructural features to the sensing performance of the layers. The films proved sensitive to ethanol and carbon monoxide and ammonia. In the case of niobium addition, it was shown that annealing temperature and niobium content strongly influence the gas response of the films converting a n-type response, which is typical of pure TiO2 and of most of metal-oxide sensors, to a p-type response; this peculiarity is crucial for the discrimination of different gases. In the case of tantalum addition, the annealing treatment at 800 °C led only to a phase transformation that reduced the sensing performance of the layer. High sensitivity to CO is achieved with anatase or mixed anatase and rutile phases, while the rutile phase only exhibit a low gas sensitivity. © 2005 Elsevier B.V. All rights reserved.
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| 2. |
- Comini, Elisabetta, et al.
(författare)
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Metal oxide nanoscience and nanotechnology for chemical sensors
- 2013
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier BV. - 0925-4005 .- 1873-3077. ; 179, s. 3-20
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Tidskriftsartikel (refereegranskat)abstract
- This paper focuses on the capabilities and development prospects of nanostructured metal oxides (MOX) representing the most versatile and richest class of materials in terms of electronic structure and structural, chemical, and physical properties. MOX nano-materials with controlled composition, surface terminations, and crystalline structures to be used as chemical sensors as a new area in analytical chemistry and instrument engineering are discussed. Their principles of operation, and basic characteristics are outlined and main applications of MOX sensor technology are presented. © 2012 Elsevier B.V. All rights reserved.
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| 3. |
- Ongo, E, et al.
(författare)
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Chemometric discrimination of philippine civet coffee using electronic nose and gas chromatography mass spectrometry
- 2012
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Ingår i: Procedia Engineering. - : Elsevier BV. - 1877-7058. ; 47, s. 977-980
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Tidskriftsartikel (refereegranskat)abstract
- This study presents a practical and promising approach to profile the headspace aroma attributes of Philippine civet coffee using electronic nose (E-nose) and gas chromatography mass spectrometry (GCMS). Chemometric pattern method was applied to enhance the discrimination of civet coffee against its control coffee beans (not eaten by civet animal). E-nose analysis revealed that aroma characteristic is one of the most important quality indicators of civet coffee. The result was supported by GCMS analysis. The chromatographic fingerprints indicated that civet coffee differed with their control beans in terms of composition and concentration of individual volatile constituents. Chemometric discrimination of E-nose and GCMS data demonstrated a clearly separated civet from their control coffees indicating that cultivar and geographic origins dictate the aroma and volatiles variations in coffee.
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| 4. |
- Ponzoni, Andrea, et al.
(författare)
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Nanostructured Metal Oxide Gas Sensors, a Survey of Applications Carried out at SENSOR Lab, Brescia (Italy) in the Security and Food Quality Fields
- 2012
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Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 12:12, s. 17023-17045
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Tidskriftsartikel (refereegranskat)abstract
- In this work we report on metal oxide (MOX) based gas sensors, presenting the work done at the SENSOR laboratory of the CNR-IDASC and University of Brescia, Italy since the 80s up to the latest results achieved in recent times. In particular we report the strategies followed at SENSOR during these 30 years to increase the performance of MOX sensors through the development of different preparation techniques, from Rheotaxial Growth Thermal Oxidation (RGTO) to nanowire technology to address sensitivity and stability, and the development of electronic nose systems and pattern recognition techniques to address selectivity. We will show the obtained achievement in the context of selected applications such as safety and security and food quality control.
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| 5. |
- Sberveglieri, Giorgio, et al.
(författare)
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Synthesis and integration of tin oxide nanowires into an electronic nose
- 2012
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Ingår i: Vacuum. - : Elsevier BV. - 0042-207X .- 1879-2715. ; 86:5, s. 532-535
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Tidskriftsartikel (refereegranskat)abstract
- Single crystal nanostructures of semiconducting tin oxides have been fabricated and characterized as sensing materials for implementation in an electronic nose. The nanowires exhibit exceptional crystalline quality and a very high length-to-width ratio, resulting in enhanced sensing capability as well as long-term material stability for prolonged operation. A sensing device based on SnO2 nanowires has been fabricated and comparatively tested in an array of chemical sensor with conventional thin film sensing device. Preliminary measurements ethanol/water mixtures demonstrate that nanowire-based sensors can be favourably implemented in the electronic nose and that they perform comparably with the conventional thin film layers.
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| 6. |
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| 7. |
- Bianchi, F., et al.
(författare)
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Differentiation of the volatile profile of microbiologically contaminated canned tomatoes by dynamic headspace extraction followed by gas chromatography-mass spectrometry analysis
- 2009
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Ingår i: Talanta. - : Elsevier BV. - 0039-9140 .- 1873-3573. ; 77:3, s. 962-970
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Tidskriftsartikel (refereegranskat)abstract
- The aromatic profile of microbiologically contaminated canned tomatoes was analyzed by the dynamic headspace extraction technique coupled with gas chromatography-mass spectrometry. Canned tomatoes contaminated with Escherichia coli, Saccharomyces cerevisiae and Aspergillus carbonarius were analyzed after 2 and 7 days. About 100 volatiles were detected, among which alcohols, aldehydes and ketones were the most abundant compounds. Gas chromatographic peak areas were used for statistical purposes. First, principal component analysis was carried out in order to visualize data trends and clusters. Then, linear discriminant analysis was performed in order to detect the set of volatile compounds ables to differentiate groups of analyzed samples. Five volatile compounds, i.e. ethanol, beta-myrcene,o-methyl styrene, 6-methyl-5-hepten-2-ol and 1-octanol, were found to be able to better discriminate between uncontaminated and contaminated samples. Prediction ability of the calculated model was estimated to be 100% by the "leave-one-out" cross-validation. An electronic nose device was then used to analyze the same contaminated and not contaminated canned tomato samples. Preliminary results were compared with those obtained by dynamic headspace gas chromatography-mass spectrometry, showing a good agreement.
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| 8. |
- Comini, Elisabetta, et al.
(författare)
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Highly sensitive single crystalline metal oxide nanowires gas sensors
- 2006
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Ingår i: Proceedings of the 2006 Conference on Optoelectronic and Microelectronic Materials and Devices. - Piscataway, NJ : IEEE Communications Society. - 1424405785 - 9781424405787 ; , s. 315-320
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Konferensbidrag (refereegranskat)abstract
- Interest in nanowires of metal oxide oxides has been exponentially growing in the last years, due to the attracting potential of application in electronic, optical and sensor field. We have focused our attention on the sensing properties of semiconducting nanowires as conductometric and optical gas sensors. Single crystal nanostructures In2O3, SnO 2, and ZnO were synthesized to explore and study their capability in form of multi-nanowires sensors. © 2006 IEEE.
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| 9. |
- Comini, Elisabetta, et al.
(författare)
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Metal oxide nanowires : Preparation and application in gas sensing
- 2009
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Ingår i: Journal of Molecular Catalysis A. - : Elsevier BV. - 1381-1169 .- 1873-314X. ; 305:1-2, s. 170-177
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Tidskriftsartikel (refereegranskat)abstract
- Quasi one-dimensional nanowires of metal oxides are promising for the development of nano-devices. Sn, In, and Zn oxides were produced in form of single-crystalline nanowires through condensation from vapor phase. Furthermore longitudinal and radial heterostructures have been prepared. Nanowires growth occurs in controlled condition and allows the exploitation of size reduction effects on the electrical response to gases. Preparation, microstructural, morphological and electrical characterizations of nanowires are presented and the peculiarities of these innovative structures are highlighted. © 2009 Elsevier B.V. All rights reserved.
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| 10. |
- Concina, Isabella, et al.
(författare)
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Alicyclobacillus spp Detection in soft drinks by Electronic Nose
- 2010
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Ingår i: Food Research International. - : Elsevier BV. - 0963-9969 .- 1873-7145. ; 43:8, s. 2108-214
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Tidskriftsartikel (refereegranskat)abstract
- In this paper the skill of an electronic nose to early diagnose the natural contamination by Alicyclobacillus spp in commercial flavoured drinks is presented The instrument was able to identify contaminated products at very low bacterial loads (tens of copies/ml) with an excellent classification rate (almost 100%) The identification of Alicyclobacillus spp by means of the electronic nose was not based on the analysis of the secondary metabolites as it is done by classical analytical techniques thus allowing a surprising capability in recognising the contaminated products at early stage of growth This study strongly suggests the use of the Electronic Noses as screening tools in industrial quality control laboratories but at the same time it underlines some limits still present in the technology
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