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| 2. |
- Berti, Francesca, et al.
(författare)
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One-Dimensional Polyaniline Nanotubes for Enhanced Chemical and Biochemical Sensing
- 2011
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Ingår i: Sensors and Microsystems. - Dordrecht : Springer Netherlands. - 9789400713239 ; , s. 311-315
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- In this work we explored a simple, cheap and fast route to grow polyaniline (PANI) nanotubes arranged in an ordered structure directly on an electrode surface by electrochemical polymerisation. The deposited nanostructures were electrochemically and morphologically characterised and then used as a functional substrate for biochemical sensing by combining the intrinsic advantages of nanostructures as optimal transducers and the well known benefits of molecularly imprinted polymers (MIPs) as receptors. The hybrid nanostructured-MIP sensor was applied to the molecular recognition of catechol. Moreover, a gas sensing application was also investigated by exploiting resistance variation of the polymer in presence of different gases (CO, NO2, NH3 and ethanol).
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| 3. |
- 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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| 4. |
- 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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| 5. |
- 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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| 6. |
- Galstyan, Vardan, et al.
(författare)
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Fabrication and investigation of gas sensing properties of Nb-doped TiO 2 nanotubular arrays
- 2012
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Ingår i: Nanotechnology. - : IOP Publishing. - 0957-4484 .- 1361-6528. ; 23:23
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Tidskriftsartikel (refereegranskat)abstract
- Synthesis of Nb-containing titania nanotubular arrays at room temperature by electrochemical anodization is reported. Crystallization of pure and Nb-doped TiO 2 nanotubes was carried out by post-growth annealing at 400°C. The morphology of the tubes obtained was characterized by scanning electron microscopy (SEM). Crystal structure and composition of tubes were investigated by glancing incidence x-ray diffraction (GIXRD) and total reflection x-ray fluorescence (TXRF). For the first time gas sensing characteristics of Nb-doped TiO 2 nanotubes were investigated and compared to those of undoped nanotubes. The functional properties of nanotubular arrays towards CO, H 2, NO 2, ethanol and acetone were tested in a wide range of operating temperature. The introduction of Nb largely improves conductivity and enhances gas sensing performances of TiO 2 nanotubes. © 2012 IOP Publishing Ltd.
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| 7. |
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| 8. |
- Ponzoni, Andrea, et al.
(författare)
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Metal oxide nanowire and thin-film-based gas sensors for chemical warfare simulants detection
- 2008
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Ingår i: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 8:6, s. 735-742
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Tidskriftsartikel (refereegranskat)abstract
- This work concerns with metal oxide (MOX) gas sensors based on nanowires and thin films. We focus on chemical warfare agents (CWAs) detection to compare these materials from the functional point-of-view. We work with different chemicals including simulants for Sarin nerve agents, vescicant gases, cyanide agents, and analytes such as ethanol, acetone, ammonia, and carbon monoxide that can be produced by everyday activities causing false alarms. Explorative data analysis has been used to demonstrate the different sensing performances of nanowires and thin films. Within the chosen application, our analysis reveal that the introduction of nanowires inside the array composed by thin films can improve its sensing capability. Cyanide simulants have been detected at concentrations close to 1 ppm, lower than the Immediately Dangerous for Life and Health (IDLH) value of the respective warfare agent. Higher sensitivity has been obtained to simulants for Sarin and vescicant gases, which have been detected at concentrations close or even lower than 100 ppb. Results demonstrate the suitability of the proposed array to selectively detect CWA simulants with respect to some compounds produced by everyday activities. © 2008 IEEE.
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| 9. |
- Vomiero, Alberto, et al.
(författare)
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Controlled growth and sensing properties of in2O3 nanowires
- 2007
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Ingår i: Crystal Growth & Design. - : American Chemical Society (ACS). - 1528-7483 .- 1528-7505. ; 7:12, s. 2500-2504
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Tidskriftsartikel (refereegranskat)abstract
- Single-crystalline nanowires of indium oxide were produced under controlled conditions via condensation from the vapor phase. Seeding of the substrate through dispersion of metallic indium nanoparticles was proven effective in promoting a nanowire nucleation driven by the vapor-solid process. Nanowires with as small an average lateral dimension as 110 nm were produced, allowing the exploitation of size reduction effects on the electrical properties and the response to gases. Preparation and microstructural and electrical characterization of nanowires are presented, and the peculiarities of these innovative structures for the development of nanodevices are highlighted. © 2007 American Chemical Society.
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| 10. |
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| 11. |
- Vomiero, Alberto, et al.
(författare)
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Insight into the formation mechanism of one-dimensional indium oxide wires
- 2010
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Ingår i: Crystal Growth & Design. - : American Chemical Society (ACS). - 1528-7483 .- 1528-7505. ; 10:1, s. 140-145
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Tidskriftsartikel (refereegranskat)abstract
- Controlled growth of oxide nanowires is an emerging research field with many applications in, for example, electronics, energy production and storage, security, and life science. A great number of theoretical and experimental studies have been carried out on the model of growth of semiconducting nanowires, while the systematic analysis of oxide nanowires is still missing. We have examined the morphological and structural features Of In2O 3nanowires grown on single crystal substrate, catalyzed by gold clusters, to investigate the basic growth mechanisms of oxide nanowires. These nanowires exhibit a bodycentered cubic structure and grow along the [100] vector of the cubic crystalline cell, thus being an ideal system for modeling nanowire nucleation and growth, without any preferential direction due to cell anisotropy. Bare vapor-solid (VS) or vapor-liquid-solid (VLS), which are the commonly accepted growth mechanisms, cannot account for the complete description of oxide nanowire growth. The experimental findings can be satisfactorily explained under the hypothesis of concurrent direct VS and catalyst-mediated VLS mechanisms during nanowire growth, with the formation of high-index lateral faces which regulates longitudinal elongation at high temperature, according to the periodic bond chain (PBC) theory. 2009 American Chemical Socieiy.
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| 12. |
- Waclawik, E.R., et al.
(författare)
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Functionalised zinc oxide nanowire gas sensors: Enhanced NO 2 gas sensor response by chemical modification of nanowire surfaces
- 2012
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Ingår i: Beilstein Journal of Nanotechnology. - : Beilstein Institut. - 2190-4286. ; 3:1, s. 368-377
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Tidskriftsartikel (refereegranskat)abstract
- Surface coating with an organic self-assembled monolayer (SAM) can enhance surface reactions or the absorption of specific gases and hence improve the response of a metal oxide (MOx) sensor toward particular target gases in the environment. In this study the effect of an adsorbed organic layer on the dynamic response of zinc oxide nanowire gas sensors was investigated. The effect of ZnO surface functionalisation by two different organic molecules, tris(hydroxymethyl)aminomethane (THMA) and dodecanethiol (DT), was studied. The response towards ammonia, nitrous oxide and nitrogen dioxide was investigated for three sensor configurations, namely pure ZnO nanowires, organic-coated ZnO nanowires and ZnO nanowires covered with a sparse layer of organic-coated ZnO nanoparticles. Exposure of the nanowire sensors to the oxidising gas NO2 produced a significant and reproducible response. ZnO and THMA-coated ZnO nanowire sensors both readily detected NO2 down to a concentration in the very low ppm range. Notably, the THMA-coated nanowires consistently displayed a small, enhanced response to NO2 compared to uncoated ZnO nanowire sensors. At the lower concentration levels tested, ZnO nanowire sensors that were coated with THMA-capped ZnO nanoparticles were found to exhibit the greatest enhanced response. ΔR/R was two times greater than that for the as-prepared ZnO nanowire sensors. It is proposed that the ΔR/R enhancement in this case originates from the changes induced in the depletion-layer width of the ZnO nanoparticles that bridge ZnO nanowires resulting from THMA ligand binding to the surface of the particle coating. The heightened response and selectivity to the NO2 target are positive results arising from the coating of these ZnO nanowire sensors with organic-SAM-functionalised ZnO nanoparticles.
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