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Publications (10 of 17) Show all publications
Cindemir, U., Topalian, Z., Granqvist, C. G., Österlund, L. & Niklasson, G. (2019). Characterization of nanocrystalline-nanoporous nickel oxide thin films prepared by reactive advanced gas deposition. Materials Chemistry and Physics, 227, 98-104
Open this publication in new window or tab >>Characterization of nanocrystalline-nanoporous nickel oxide thin films prepared by reactive advanced gas deposition
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2019 (English)In: Materials Chemistry and Physics, ISSN 0254-0584, E-ISSN 1879-3312, Vol. 227, p. 98-104Article in journal (Refereed) Published
Abstract [en]

Nanocrystalline-nanoporous Ni oxide is of much interest for gas sensors and other applications. Reactive advanced gas deposition (AGD) stands out as a particularly promising technique for making thin films of this material owing to the techniques ability to separate between the growth of individual nanoparticles and their subsequent deposition to create a consolidated material on a substrate. Here we report on the characterization of Ni oxide films, made by reactive AGD, by several methods. X-ray diffractometry showed that the films had a face centered cubic NiO structure, and scanning electron microscopy indicated a compact nanoparticulate composition. X-ray photoelectron spectroscopy showed the presence of Ni3+ and demonstrated that these states became less prominent upon heat treatment in air. Extended x-ray absorption fine structure analysis elucidated the local atomic structure; in particular, data on interatomic distances and effects of annealing on local disorder showed that the Ni oxide nanoparticles crystallize upon annealing while maintaining their nanoparticle morphology, which is a crucial feature for reproducible fabrication of Ni oxide thin films for gas sensors. Importantly, several techniques demonstrated that grain growth remained modest for annealing temperatures as high as 400 degrees C for 1700-nm-thick films. The present article is a sequel to an earlier one [U. Cindemir et al., Sensors and Actuators B 242 (2017) 132-139] in which we reported on fluctuation-enhanced and conductometric gas sensing with Ni oxide films prepared by AGD.

Place, publisher, year, edition, pages
ELSEVIER SCIENCE SA, 2019
Keywords
Nickel oxide, Advanced gas deposition, EXAFS, Atomic structure, Gas sensor
National Category
Engineering and Technology
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-387223 (URN)10.1016/j.matchemphys.2019.01.058 (DOI)000466617800013 ()
Funder
EU, FP7, Seventh Framework Programme, 267234
Available from: 2019-06-25 Created: 2019-06-25 Last updated: 2020-01-31Bibliographically approved
Geremariam Welearegay, T., Diouani, M. F., Österlund, L., Borys, S., Khaled, S., Smadhi, H., . . . Ionescu, R. (2019). Diagnosis of Human Echinococcosis via Exhaled Breath Analysis: A Promise for Rapid Diagnosis of Infectious Diseases Caused by Helminths. Journal of Infectious Diseases, 219(1), 101-109
Open this publication in new window or tab >>Diagnosis of Human Echinococcosis via Exhaled Breath Analysis: A Promise for Rapid Diagnosis of Infectious Diseases Caused by Helminths
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2019 (English)In: Journal of Infectious Diseases, ISSN 0022-1899, E-ISSN 1537-6613, Vol. 219, no 1, p. 101-109Article in journal (Refereed) Published
Abstract [en]

Background: Human echinococcosis is a neglected infectious disease affecting more than 1 million people globally. Its diagnosis is expensive and difficult because of lack of adequate resources in low-resource locations, where most cases occur.

Methods: A group of volunteers diagnosed with the 2 main types of echinococcosis and corresponding control groups were recruited from hospitals in Tunisia (32 patients with cystic echinococcosis and 43 controls) and Poland (16 patients with alveolar echinococcosis and 8 controls). Breath samples were collected from all patients and analyzed by gas chromatography coupled to mass spectrometry, and a specifically developed electronic nose system.

Results: The chemical analysis revealed statistically different concentrations of 2 compounds in the breath of patients with cystic echinococcosis compared to controls, and statistically different concentrations of 7 compounds in the breath of patients with alveolar echinococcosis compared to controls. The discrimination accuracy achieved by the electronic nose system was 100% for cystic echinococcosis and 92.9% for alveolar echinococcosis, while the discrimination accuracy between these 2 patient groups was 92.1%.

Conclusion: Here we advocate a noninvasive, fast, easy-to-operate and nonexpensive diagnostic tool for the diagnosis of human echinococcosis disease through exhaled breath analysis, suitable for early diagnosis and population screening.

Keywords
echinococcosis, diagnosis, breath analysis, biomarkers, chemical sensors
National Category
Engineering and Technology
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-378686 (URN)10.1093/infdis/jiy449 (DOI)000458610200014 ()30016445 (PubMedID)
Funder
EU, Horizon 2020, 645758
Available from: 2019-03-12 Created: 2019-03-12 Last updated: 2020-02-18Bibliographically approved
Arvizu, M. A., Qu, H.-Y., Cindemir, U., Qiu, Z., Rojas González, E. A., Primetzhofer, D., . . . Niklasson, G. (2019). Electrochromic WO3 thin films attain unprecedented durability by potentiostatic pretreatment. Journal of Materials Chemistry A, 7(6), 2908-2918
Open this publication in new window or tab >>Electrochromic WO3 thin films attain unprecedented durability by potentiostatic pretreatment
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2019 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 7, no 6, p. 2908-2918Article in journal (Refereed) Published
Abstract [en]

Electrochromic windows and glass facades are able to impart energy efficiency jointly with indoor comfort and convenience. Long-term durability is essential for practical implementation of this technology and has recently attracted broad interest. Here we show that a simple potentiostatic pretreatment of sputterdeposited thin films of amorphous WO3-the most widely studied electrochromic material-can yield unprecedented durability for charge exchange and optical modulation under harsh electrochemical cycling in a Li-ion-conducting electrolyte and effectively evades harmful trapping of Li. The pretreatment consisted of applying a voltage of 6.0 V vs. Li/Li+ for several hours to a film backed by a transparent conducting In2O3: Sn layer. Associated compositional and structural modifications were probed by several techniques, and improved durability was associated with elemental intermixing at the WO3/ITO and ITO/glass boundaries as well as with carbonaceous solid-electrolyte interfacial layers on the WO3 films. Our work provides important new insights into long-term durability of ion-exchange-based devices.

Place, publisher, year, edition, pages
ROYAL SOC CHEMISTRY, 2019
National Category
Materials Chemistry
Identifiers
urn:nbn:se:uu:diva-378529 (URN)10.1039/c8ta09621j (DOI)000457893400054 ()
Funder
EU, European Research Council, 267234Swedish Research Council, 821-2012-5144Swedish Research Council, 2017-00646_9Swedish Foundation for Strategic Research , RIF14-0053
Available from: 2019-03-22 Created: 2019-03-22 Last updated: 2019-03-22Bibliographically approved
Geremariam Welearegay, T., Cindemir, U., Österlund, L. & Ionescu, R. (2018). Fabrication and characterisation of ligand-functionalised ultrapure monodispersed metal nanoparticle nanoassemblies employing advanced gas deposition technique. Nanotechnology, 29(6), Article ID 065603.
Open this publication in new window or tab >>Fabrication and characterisation of ligand-functionalised ultrapure monodispersed metal nanoparticle nanoassemblies employing advanced gas deposition technique
2018 (English)In: Nanotechnology, ISSN 0957-4484, E-ISSN 1361-6528, Vol. 29, no 6, article id 065603Article in journal (Refereed) Published
Abstract [en]

Here, we report for the first time the fabrication of ligand-functionalised ultrapure monodispersed metal nanoparticles (Au, Cu, and Pt) from their pure metal precursors using the advanced gas deposition technique. The experimental conditions during nanoparticle formation were adjusted in order to obtain ultrafine isolated nanoparticles on different substrates. The morphology and surface analysis of the as-deposited metal nanoparticles were investigated using scanning electron microscopy, x-ray diffraction and Fourier transform infra-red spectroscopy, which demonstrated the formation of highly ordered pure crystalline nanoparticles with a relatively uniform size distribution of similar to 10 nm (Au), similar to 4 nm (Cu) and similar to 3 nm (Pt), respectively. A broad range of organic ligands containing thiol or amine functional groups were attached to the nanoparticles to form continuous networks of nanoparticle-ligand nanoassemblies, which were characterised by scanning electron microscopy and x-ray photoelectron spectroscopy. The electrical resistance of the functional nanoassemblies deposited in the gap spacing of two microfabricated parallel Au electrodes patterned on silicon substrates ranged between tens of k Omega and tens of M Omega, which is suitable for use in many applications including (bio)chemical sensors, surface-enhanced Raman spectroscopy and molecular electronic rectifiers.

Place, publisher, year, edition, pages
IOP PUBLISHING LTD, 2018
Keywords
metal nanoparticles, monodispersed, advanced gas deposition, molecularly-capped metal nanoparticles, self-assembled monolayers
National Category
Engineering and Technology
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-341557 (URN)10.1088/1361-6528/aa9f65 (DOI)000419631700003 ()29206108 (PubMedID)
Available from: 2018-02-13 Created: 2018-02-13 Last updated: 2020-02-18Bibliographically approved
Welearegay, T. G., Diouani, M. F., Österlund, L., Ionescu, F., Belgacem, K., Smadhi, H., . . . Ionescu, R. (2018). Ligand-Capped Ultrapure Metal Nanoparticle Sensors for the Detection of Cutaneous Leishmaniasis Disease in Exhaled Breath. ACS Sensors, 3(12), 2532-2540
Open this publication in new window or tab >>Ligand-Capped Ultrapure Metal Nanoparticle Sensors for the Detection of Cutaneous Leishmaniasis Disease in Exhaled Breath
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2018 (English)In: ACS Sensors, Vol. 3, no 12, p. 2532-2540Article in journal (Refereed) Published
Abstract [en]

Human cutaneous leishmaniasis, although designated as one of the most neglected tropical diseases, remains underestimated due to its misdiagnosis. The diagnosis is mainly based on the microscopic detection of amastigote forms, isolation of the parasite, or the detection of LeishmaniaDNA, in addition to its differential clinical characterization; these tools are not always available in routine daily practice, and they are expensive and time-consuming. Here, we present a simple-to-use, noninvasive approach for human cutaneous leishmaniasis diagnosis, which is based on the analysis of volatile organic compounds in exhaled breath with an array of specifically designed chemical gas sensors. The study was realized on a group of n = 28 volunteers diagnosed with human cutaneous leishmaniasis and a group of n = 32 healthy controls, recruited in various sites from Tunisia, an endemic country of the disease. The classification success rate of human cutaneous leishmaniasis patients achieved by our sensors test was 98.2% accuracy, 96.4% sensitivity, and 100% specificity. Remarkably, one of the sensors, based on CuNPs functionalized with 2-mercaptobenzoxazole, yielded 100% accuracy, 100% sensitivity, and 100% specificity for human cutaneous leishmaniasis discrimination. While AuNPs have been the most extensively used in metal nanoparticle–ligand sensing films for breath sensing, our results demonstrate that chemical sensors based on ligand-capped CuNPs also hold great potential for breath volatile organic compounds detection. Additionally, the chemical analysis of the breath samples with gas chromatography coupled to mass spectrometry identified nine putative breath biomarkers for human cutaneous leishmaniasis.

Keywords
biomarkers; chemical gas sensors; diagnosis; exhaled breath analysis; human cutaneous leishmaniasis; metal nanoparticles−ligand nanoassemblies
National Category
Engineering and Technology
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-370080 (URN)10.1021/acssensors.8b00759 (DOI)000454962400009 ()30403135 (PubMedID)
Projects
Tropsense
Funder
EU, Horizon 2020, 645758
Note

De tre första författarna delar förstaförfattarskapet.

Available from: 2018-12-18 Created: 2018-12-18 Last updated: 2020-02-18Bibliographically approved
Qu, H.-Y., Primetzhofer, D., Arvizu, M. A., Qiu, Z., Cindemir, U., Granqvist, C. G. & Niklasson, G. A. (2017). Electrochemical Rejuvenation of Anodically Coloring Electrochromic Nickel Oxide Thin Films. ACS Applied Materials and Interfaces (9), 42420-42424
Open this publication in new window or tab >>Electrochemical Rejuvenation of Anodically Coloring Electrochromic Nickel Oxide Thin Films
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2017 (English)In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, no 9, p. 42420-42424Article in journal (Refereed) Published
Abstract [en]

Nickel oxide thin films are of major importance as anodically coloring components in electrochromic smart windows with applications in energy-efficient buildings. However, the optical performance of these films degrades upon extended electrochemical cycling, which has hampered their implementation. Here, we use a potentiostatic treatment to rejuvenate degraded nickel oxide thin films immersed in electrolytes of LiClO4 in propylene carbonate. Time-of-flight elastic recoil detection analysis provided unambiguous evidence that both Li+ ions and chlorine-based ions participate in the rejuvenation process. Our work provides new perspectives for developing ion-exchange-based devices embodying nickel oxide.

Keywords
electrochromism, nickel oxide, thin film, electrochemical rejuvenation, ToF-ERDA
National Category
Engineering and Technology Nano Technology
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-336541 (URN)10.1021/acsami.7b13815 (DOI)000418204300003 ()29164852 (PubMedID)
Funder
Swedish Foundation for Strategic Research , SSF-RIF14-0053Swedish Research Council, 821-2012-5144
Available from: 2017-12-14 Created: 2017-12-14 Last updated: 2019-02-01Bibliographically approved
Cindemir, U., Trawka, M., Smulko, J., Granqvist, C.-G., Österlund, L. & Niklasson, G. . (2017). Fluctuation-enhanced and conductometric gas sensing with nanocrystalline NiO thin films: A comparison. Sensors and actuators. B, Chemical, 242, 132-139
Open this publication in new window or tab >>Fluctuation-enhanced and conductometric gas sensing with nanocrystalline NiO thin films: A comparison
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2017 (English)In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 242, p. 132-139Article in journal (Refereed) Published
Abstract [en]

Nanocrystalline thin films of NiO were prepared by advanced reactive gas deposition, and their responses to formaldehyde, ethanol and methane gases were studied via fluctuation-enhanced and conductometric methods Thin films with thicknesses in the 200–1700-nm range were investigated in as-deposited form and after annealing at 400 and 500◦C. Morphological and structural analyses showed porous deposits with NiO nanocrystals having face-centered cubic structure. Quantitative changes in frequency-dependent resistance fluctuations as well as in DC resistance were recorded upon exposure to formaldehyde, ethanol and methane at 200◦C. The response to formaldehyde was higher than that to ethanol while the response to methane was low, which indicates that the NiO films exhibit significant selectivity towards different gaseous species. These results can be reconciled with the fact that formaldehyde has a nucleophilic group, ethanol is an electron scavenger, and methane is hard to either reduce or oxidize. The gas-induced variations in DC resistance and resistance fluctuations were in most cases similar and consistent.

National Category
Engineering and Technology
Research subject
Engineering Science with specialization in Solid State Physics
Identifiers
urn:nbn:se:uu:diva-307575 (URN)10.1016/j.snb.2016.11.015 (DOI)000393267700018 ()
Funder
EU, European Research CouncilEU, Horizon 2020, 645758
Available from: 2016-11-17 Created: 2016-11-17 Last updated: 2020-02-18Bibliographically approved
Lentka, L., Kotarski, M., Smulko, J., Cindemir, U., Topalian, Z., Granqvist, C.-G., . . . Ionescu, R. (2016). Fluctuation-enhanced sensing with organically functionalized gold nanoparticle gas sensors targeting biomedical applications. Talanta: The International Journal of Pure and Applied Analytical Chemistry, 160, 9-14
Open this publication in new window or tab >>Fluctuation-enhanced sensing with organically functionalized gold nanoparticle gas sensors targeting biomedical applications
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2016 (English)In: Talanta: The International Journal of Pure and Applied Analytical Chemistry, ISSN 0039-9140, E-ISSN 1873-3573, Vol. 160, p. 9-14Article in journal (Refereed) Published
Abstract [en]

Detection of volatile organic compounds is a useful approach to non-invasive diagnosis of diseases through breath analysis. Our experimental study presents a newly developed prototype gas sensor, based on organically-functionalized gold nanoparticles, and results on formaldehyde detection using fluctuation-enhanced gas sensing. Formaldehyde was easily detected via intense fluctuations of the gas sensor's resistance, while the cross-influence of ethanol vapor (a confounding factor in exhaled breath, related to alcohol consumption) was negligible.

Keywords
Organically-functionalized gold nanoparticles; Formaldehyde detection; Fluctuation enhanced sensing; Flicker noise
National Category
Chemical Engineering
Identifiers
urn:nbn:se:uu:diva-302550 (URN)10.1016/j.talanta.2016.06.063 (DOI)000383524400002 ()27591581 (PubMedID)
Funder
EU, European Research Council, 267234
Available from: 2016-09-06 Created: 2016-09-06 Last updated: 2017-11-21Bibliographically approved
Cindemir, U., Lansåker, P. C., Österlund, L., Niklasson, G. A. & Granqvist, C.-G. (2016). Sputter-Deposited Indium-Tin Oxide Thin Films for Acetaldehyde Gas Sensing. Coatings, 6(2), Article ID 19.
Open this publication in new window or tab >>Sputter-Deposited Indium-Tin Oxide Thin Films for Acetaldehyde Gas Sensing
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2016 (English)In: Coatings, ISSN 2079-6412, Vol. 6, no 2, article id 19Article in journal (Refereed) Published
Abstract [en]

Reactive dual-target DC magnetron sputtering was used to prepare In-Sn oxide thin films with a wide range of compositions. The films were subjected to annealing post-treatment at 400 degrees C or 500 degrees C for different periods of time. Compositional and structural characterizations were performed by X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, Rutherford backscattering and scanning electron microscopy. Films were investigated for gas sensing at 200 degrees C by measuring their resistance response upon exposure to acetaldehyde mixed with synthetic air. We found that the relative indium-to-tin content was very important and that measurable sensor responses could be recorded at acetaldehyde concentrations down to 200 ppb, with small resistance drift between repeated exposures, for both crystalline SnO2-like films and for amorphous films consisting of about equal amounts of In and Sn. We also demonstrated that it is not possible to prepare crystalline sensors with intermediate indium-to-tin compositions by sputter deposition and post-annealing up to 500 degrees C.

Keywords
indium tin oxide, magnetron sputtering, gas sensor, acetaldehyde
National Category
Materials Engineering
Identifiers
urn:nbn:se:uu:diva-299731 (URN)10.3390/coatings6020019 (DOI)000378428700006 ()
Funder
EU, FP7, Seventh Framework Programme, 267234
Available from: 2016-07-26 Created: 2016-07-26 Last updated: 2018-08-30Bibliographically approved
Cindemir, U. (2016). Thin films for indoor air monitoring: Measurements of Volatile Organic Compounds. (Doctoral dissertation). Uppsala: Acta Universitatis Upsaliensis
Open this publication in new window or tab >>Thin films for indoor air monitoring: Measurements of Volatile Organic Compounds
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Volatile organic compounds (VOCs) in the indoor air have adverse effects on the dwellers residing in a building or a vehicle. One of these effects is called sick building syndrome (SBS). SBS refers to situations in which the users of a building develop acute health effects and discomfort depending on the time they spend inside some buildings without having any specific illness. Furthermore, monitoring volatile organic compounds could lead to early diagnosis of specific illnesses through breath analysis. Among those VOCs formaldehyde, acetaldehyde can be listed.

In this thesis, VOC detecting thin film sensors have been investigated. Such sensors have been manufactured using semiconducting metal oxides, ligand activated gold nanoparticles and Graphene/TiO2 mixtures. Advanced gas deposition unit, have been used to produce NiO thin films and Au nanoparticles. DC magnetron sputtering has been used to produce InSnO and VO2 thin film sensors. Graphene/TiO2 sensors have been manufactured using doctor-blading.

While presenting the results, first, material characterization details are presented for each sensor, then, gas sensing results are presented. Morphologies, crystalline structures and chemical properties have been analyzed using scanning electron microscopy, X-ray diffraction and X-ray photo electron spectroscopy. Furthermore, more detailed analyses have been performed on NiO samples using extended X-ray absorption fine structure method and N2 adsorption measurements. Gas sensing measurements were focused on monitoring formaldehyde and acetaldehyde. However, responses ethanol and methane were measured in some cases to monitor selectivity. Graphene/TiO2 samples were used to monitor NO2 and NH3. For NiO thin film sensors and Au nano particles, fluctuation enhanced gas sensing is also presented in addition to conductometric measurements. 

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2016. p. 78
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1422
Keywords
gas sensor, thin film, adcanced gas depostion, sputter deposition, nickel oxide, gold nanoparticles, indium tin oxide, acetaldehyde, formaldehyde
National Category
Nano Technology
Identifiers
urn:nbn:se:uu:diva-302558 (URN)978-91-554-9683-8 (ISBN)
Public defence
2016-10-21, Room Å2001, Ångströmlaboratoriet, Lägerhyddsv 1, 13:15 (English)
Opponent
Supervisors
Funder
EU, FP7, Seventh Framework Programme, 267234
Available from: 2016-09-28 Created: 2016-09-06 Last updated: 2016-10-14Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-8147-9778

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