Records |
Author |
Lenaerts, S.; Honoré, M.; Huyberechts, G.; Roggen, J.; Maes, G. |
Title |
In situ infrared and electrical characterization of tin dioxide gas sensors in nitrogen/oxygen mixtures at temperatures up to 720 K |
Type |
A1 Journal article |
Year |
1994 |
Publication |
Sensors and actuators : B : chemical |
Abbreviated Journal |
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Volume |
19 |
Issue |
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Pages |
478-482 |
Keywords ![sorted by Keywords field, descending order (down)](img/sort_desc.gif) |
A1 Journal article |
Abstract |
FT-IR spectroscopy and impedance measurements of tin dioxide sensor materials at working temperatures up to 450 °C in atmospheres with varying O2/N2 ratio are used as an in situ probe to study the interactions at the surface of the semiconducting oxide. Every diminution in the oxygen content above the sample induces a broad IR absorption band (X-band) between 2300700 cm−1 with a few small peaks in the 1400850 cm−1 region of the spectrum superimposed on it. The X-band results from the enchanced electron concentration in the bulk of the tin dioxide domain. The fine structure is due to the absorption of several kinds of surface oxygen species associated vibration modes. The porous tin dioxide consists of domains were the outward shell is depleted of electrons by the formation of adsorbed O− species on oxygen surface sites, SO(O− species. In our proposed model for the impedance data this gives rise to a parallel RpCp circuit for the domain boundary characteristics and to an Rs parameter for the intradomain resistance. The evolution of these IR and impedance spectroscopic effects with temperature and oxygen content is used to set up, to confirm and refine a physicochemical operation model of tin dioxide gas sensor. This model consists of a sensitizing reaction sequence in the presence of oxygen and a gas-detection reaction sequence when a reducing gas is present. Based on this model, the principal disadvantages of this type of gas sensor become clear. Every factor that influences the concentration of SO(O−) species, causes a conductance modification. If we can control and direct the nature, the number and the arrangement of the tin dioxide domains, a directed development and improvement of the sensor characteristics is possible. |
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Corporate Author |
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Publisher |
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Place of Publication |
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Language |
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Wos |
A1994NN90000040 |
Publication Date |
2002-07-25 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0925-4005 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
Call Number |
UA @ admin @ c:irua:82014 |
Serial |
5962 |
Permanent link to this record |
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Author |
Honoré, M.; Lenaerts, S.; Desmet, J.; Huyberechts, G.; Roggen, J. |
Title |
Synthesis and characterization of tin dioxide powders for the realization of thick-film gas sensors |
Type |
A1 Journal article |
Year |
1994 |
Publication |
Sensors and actuators : B : chemical |
Abbreviated Journal |
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Volume |
19 |
Issue |
|
Pages |
621-624 |
Keywords ![sorted by Keywords field, descending order (down)](img/sort_desc.gif) |
A1 Journal article |
Abstract |
Semiconductor gas sensors produced with screen-printing techniques and based on home-made tin dioxide inks are presented. The ink consists of home-made tin dioxide powder added to a polymer solution to make it screen printable on 96% alumina substrates. The major work is performed on the preparation and the characterization of pure undoped tin dioxide powder produced by two different synthetic pathways. Inks prepared with powders from each method are consecutively handled in an identical way to obtain gas sensors. The sensor response towards different gases is measured and compared for both types of starting materials. |
Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
A1994NN90000073 |
Publication Date |
2002-07-25 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0925-4005 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
Call Number |
UA @ admin @ c:irua:82013 |
Serial |
5996 |
Permanent link to this record |
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Author |
Smets, B.; Boschker, H.T.S.; Wetherington, M.T.; Lelong, G.; Hidalgo-Martinez, S.; Polerecky, L.; Nuyts, G.; De Wael, K.; Meysman, F.J.R. |
Title |
Multi-wavelength Raman microscopy of nickel-based electron transport in cable bacteria |
Type |
A1 Journal article |
Year |
2024 |
Publication |
Frontiers in microbiology |
Abbreviated Journal |
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Volume |
15 |
Issue |
|
Pages |
1208033-16 |
Keywords ![sorted by Keywords field, descending order (down)](img/sort_desc.gif) |
A1 Journal article |
Abstract |
Cable bacteria embed a network of conductive protein fibers in their cell envelope that efficiently guides electron transport over distances spanning up to several centimeters. This form of long-distance electron transport is unique in biology and is mediated by a metalloprotein with a sulfur-coordinated nickel (Ni) cofactor. However, the molecular structure of this cofactor remains presently unknown. Here, we applied multi-wavelength Raman microscopy to identify cell compounds linked to the unique cable bacterium physiology, combined with stable isotope labeling, and orientation-dependent and ultralow-frequency Raman microscopy to gain insight into the structure and organization of this novel Ni-cofactor. Raman spectra of native cable bacterium filaments reveal vibrational modes originating from cytochromes, polyphosphate granules, proteins, as well as the Ni-cofactor. After selective extraction of the conductive fiber network from the cell envelope, the Raman spectrum becomes simpler, and primarily retains vibrational modes associated with the Ni-cofactor. These Ni-cofactor modes exhibit intense Raman scattering as well as a strong orientation-dependent response. The signal intensity is particularly elevated when the polarization of incident laser light is parallel to the direction of the conductive fibers. This orientation dependence allows to selectively identify the modes that are associated with the Ni-cofactor. We identified 13 such modes, some of which display strong Raman signals across the entire range of applied wavelengths (405–1,064 nm). Assignment of vibrational modes, supported by stable isotope labeling, suggest that the structure of the Ni-cofactor shares a resemblance with that of nickel bis(1,2-dithiolene) complexes. Overall, our results indicate that cable bacteria have evolved a unique cofactor structure that does not resemble any of the known Ni-cofactors in biology. |
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Wos |
001189511900001 |
Publication Date |
2024-03-08 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1664-302x |
ISBN |
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Additional Links |
UA library record; WoS full record |
Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: NA |
Call Number |
UA @ admin @ c:irua:205115 |
Serial |
9214 |
Permanent link to this record |
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Author |
Pankratov, D.; Hidalgo Martinez, S.; Karman, C.; Gerzhik, A.; Gomila, G.; Trashin, S.; Boschker, H.T.S.; Geelhoed, J.S.; Mayer, D.; De Wael, K.; Meysman, F.J.R. |
Title |
The organo-metal-like nature of long-range conduction in cable bacteria |
Type |
A1 Journal article |
Year |
2024 |
Publication |
Bioelectrochemistry: an international journal devoted to electrochemical aspects of biology and biological aspects of electrochemistry |
Abbreviated Journal |
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Volume |
157 |
Issue |
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Pages |
108675-10 |
Keywords ![sorted by Keywords field, descending order (down)](img/sort_desc.gif) |
A1 Journal article |
Abstract |
Cable bacteria are filamentous, multicellular microorganisms that display an exceptional form of biological electron transport across centimeter-scale distances. Currents are guided through a network of nickel-containing protein fibers within the cell envelope. Still, the mechanism of long-range conduction remains unresolved. Here, we characterize the conductance of the fiber network under dry and wet, physiologically relevant, conditions. Our data reveal that the fiber conductivity is high (median value: 27 S cm−1; range: 2 to 564 S cm−1), does not show any redox signature, has a low thermal activation energy (Ea = 69 ± 23 meV), and is not affected by humidity or the presence of ions. These features set the nickel-based conduction mechanism in cable bacteria apart from other known forms of biological electron transport. As such, conduction resembles that of an organic semi-metal with a high charge carrier density. Our observation that biochemistry can synthesize an organo-metal-like structure opens the way for novel bio-based electronic technologies. |
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Corporate Author |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
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Publication Date |
2024-02-25 |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1567-5394 |
ISBN |
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Additional Links |
UA library record |
Impact Factor |
5 |
Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: 5; 2024 IF: 3.346 |
Call Number |
UA @ admin @ c:irua:205117 |
Serial |
9215 |
Permanent link to this record |