Extremely sensitive and selective NO probe based on villi-like WO 3 nanostructures for application to exhaled breath analyzers

Hi Gyu Moon, You Rim Choi, Young Seok Shim, Kwon Il Choi, Jong Heun Lee, Jin Sang Kim, Seok Jin Yoon, Hyung Ho Park, Chong Yun Kang, Ho Won Jang

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72 Citations (Scopus)


Self-assembled WO3 thin film nanostructures with 1-dimensional villi-like nanofingers (VLNF) have been synthesized on the SiO2/Si substrate with Pt interdigitated electrodes using glancing angle deposition (GAD). Room-temperature deposition of WO3 by GAD resulted in anisotropic nanostructures with large aspect ratio and porosity having a relative surface area, which is about 32 times larger than that of a plain WO3 film. A WO3 VLNF sensor shows extremely high response to nitric oxide (NO) at 200 C in 80% of relative humidity atmosphere, while responses of the sensor to ethanol, acetone, ammonia, and carbon monoxide are negligible. Such high sensitivity and selectivity to NO are attributed to the highly efficient modualtion of potential barriers at narrow necks between individual WO3 VLNF and the intrinsically high sensitivity of WO 3 to NO. The theoretical detection limit of the sensor for NO is expected to be as low as 88 parts per trillion (ppt). Since NO is an approved biomarker of chronic airway inflammation in asthma, unprecedentedly high response and selectivity, and ppt-level detection limit to NO under highly humid environment demonstrate the great potential of the WO3 VLNF for use in high performance breath analyzers.

Original languageEnglish
Pages (from-to)10591-10596
Number of pages6
JournalACS Applied Materials and Interfaces
Issue number21
Publication statusPublished - 2013 Nov 13

All Science Journal Classification (ASJC) codes

  • Materials Science(all)


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