Highly selective ppb-level detection of NH<inf>3</inf> and NO<inf>2</inf> gas using patterned porous channels of ITO nanoparticles

Dong Jin Lee, Jonghyurk Park, Hyun Soo Kim, Do Hoon Lee, Minjun Park, Hochan Chang, Joon Hyung Jin, Jong Ryeul Sohn, Kwang Heo, Byung Yang Lee

Research output: Contribution to journalArticle

15 Citations (Scopus)


We demonstrate the formation of micro-patterned porous electronic channels of tin-doped indium oxide nanoparticles (ITO NPs) and their utilization as sensor transducers for the detection of NH<inf>3</inf> and NO<inf>2</inf> gas in air. The ITO NP channels were formed by dipping a molecularly patterned solid substrate into an ITO NP suspension and then pulling it vertically at a precisely controlled speed. The ITO NPs were self-assembled on the intended regions with high definition, as the NPs were selectively adsorbed on the polar SiO<inf>2</inf> regions avoiding the nonpolar regions. The thickness of the assembled ITO NP patterns could be modulated by controlling the pulling speed. The NPs formed a dense percolated network through which current could flow without any post-treatment such as heat annealing. By forming electrodes on the assembled ITO NP patterns, we fabricated sensor transducers for the detection of ammonia and nitrogen dioxide. The sensor showed a highly sensitive detection of NH<inf>3</inf> and NO<inf>2</inf> gas down to ppb-level. Furthermore, the sensor response changed in opposite direction to reducing NH<inf>3</inf> and oxidizing NO<inf>2</inf> gases, which shows that our sensor can be utilized in the selective detection of NH<inf>3</inf> and NO<inf>2</inf>.

Original languageEnglish
Pages (from-to)1-6
Number of pages6
JournalSensors and Actuators, B: Chemical
Publication statusPublished - 2015 Apr 23



  • Gas sensor
  • Indium tin oxide
  • Nanoparticle
  • Self-assembly

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics
  • Electronic, Optical and Magnetic Materials
  • Metals and Alloys
  • Surfaces, Coatings and Films
  • Materials Chemistry
  • Instrumentation

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