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- Comini, Elisabetta, et al.
(author)
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Effects of Ta/Nb-doping on titania-based thin films for gas-sensing
- 2005
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In: Sensors and actuators. B, Chemical. - : Elsevier BV. - 0925-4005 .- 1873-3077. ; 108:1-2 SPEC. ISS., s. 21-28
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Journal article (peer-reviewed)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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| 7. |
- Bianchi, F., et al.
(author)
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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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In: Talanta. - : Elsevier BV. - 0039-9140 .- 1873-3573. ; 77:3, s. 962-970
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Journal article (peer-reviewed)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.
(author)
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Highly sensitive single crystalline metal oxide nanowires gas sensors
- 2006
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In: 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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Conference paper (peer-reviewed)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.
(author)
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Metal oxide nanowires : Preparation and application in gas sensing
- 2009
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In: Journal of Molecular Catalysis A. - : Elsevier BV. - 1381-1169 .- 1873-314X. ; 305:1-2, s. 170-177
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Journal article (peer-reviewed)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.
(author)
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Alicyclobacillus spp Detection in soft drinks by Electronic Nose
- 2010
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In: Food Research International. - : Elsevier BV. - 0963-9969 .- 1873-7145. ; 43:8, s. 2108-214
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Journal article (peer-reviewed)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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