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Publikācija: Colorimetric Gas Detection by the Varying Thickness of a Thin Film of Ultrasmall PTSA-Coated TiO2 Nanoparticles on a Si Substrate

Publication Type Scientific article indexed in SCOPUS or WOS database
Funding for basic activity Unknown
Defending: ,
Publication language English (en)
Title in original language Colorimetric Gas Detection by the Varying Thickness of a Thin Film of Ultrasmall PTSA-Coated TiO2 Nanoparticles on a Si Substrate
Field of research 2. Engineering and technology
Sub-field of research 2.5 Materials engineering
Authors Urmas Joost
Andris Šutka
Meeri Visnapuu
Aile Tamm
Meeri Lembinen
Mikk Antsov
Kathriin Utt
Krisjanis Smits
Ergo Nõmmiste
Vambola Kisand
Keywords colorimetric gas sensing; p-toluenesulfonic acid (PTSA); TiO2 nanoparticles
Abstract Colorimetric gas sensing is demonstrated by thin films based on ultrasmall TiO2 nanoparticles (NPs) on Si substrates. The NPs are bound into the film by p-toluenesulfonic acid (PTSA) and the film is made to absorb volatile organic compounds (VOCs). Since the color of the sensing element depends on the interference of reflected light from the surface of the film and from the film/silicon substrate interface, colorimetric detection is possible by the varying thickness of the NP-based film. Indeed, VOC absorption causes significant swelling of the film. Thus, the optical path length is increased, interference wavelengths are shifted and the refractive index of the film is decreased. This causes a change of color of the sensor element visible by the naked eye. The color response is rapid and changes reversibly within seconds of exposure. The sensing element is extremely simple and cheap, and can be fabricated by common coating processes.
DOI: 10.3762/bjnano.8.25
Hyperlink: http://www.beilstein-journals.org/bjnano/single/articleFullText.htm?publicId=2190-4286-8-25 
Reference Joost, U., Šutka, A., Visnapuu, M., Tamm, A., Lembinen, M., Antsov, M., Utt, K., Smits, K., Nõmmiste, E., Kisand, V. Colorimetric Gas Detection by the Varying Thickness of a Thin Film of Ultrasmall PTSA-Coated TiO2 Nanoparticles on a Si Substrate. Beilstein Journal of Nanotechnology, 2017, Vol.8, pp.229-236. Available from: doi:10.3762/bjnano.8.25
Additional information Citation count:
ID 24316