Thin films composed of multiwalled carbon nanotubes, gold nanoparticles and myoglobin for humidity detection at room temperature

Zhi Mei Qi, Mingdeng Wei, Itaru Honma, Haoshen Zhou

Research output: Contribution to journalArticlepeer-review

12 Citations (Scopus)

Abstract

Optically transparent and electrically conductive nanocomposite thin films consisting of multiwalled carbon nanotubes (MWCNTs), gold nanoparticles (GNPs) and myoglobin molecules that glue GNPs and MWCNTs together are fabricated for the first time on glass substrates from aqueous solution. The nanocomposite thin film is capable of varying its resistance, impedance or optical transmittance at room temperature in response to changes in ambient humidity. The conductometric sensitivity to relative humidity (RH) of the nanocomposite thin film is compared with those of the pure and Mb-functionalized MWCNT layers. The pure MWCNT layer shows a small increase in its resistance with increasing RH due to the effect of p-type semiconducting nanotubes present in the film. In contrast, a four times higher sensitivi-ty to RH is observed for both the nanocomposite and Mb-functionalized MWCNT thin films. The sensitivity enhancement is attributable to swelling of the thin films induced by water absorption in the presence of Mb molecules, which increases the internanotube spacing and thereby causes a further increase of the film resistance. A humidity change as low as ΔRH =03% has been readily detected by conductometry using the nanocomposite thin film.

Original languageEnglish
Pages (from-to)264-269
Number of pages6
JournalChemPhysChem
Volume8
Issue number2
DOIs
Publication statusPublished - 2007 Feb 2
Externally publishedYes

Keywords

  • Gold nanoparticles
  • Myoglobin
  • Nanotechnology
  • Sensors
  • Thin films

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Physical and Theoretical Chemistry

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