A Parts per Billion (ppb) Sensor for NO 2 with Microwatt (μW) Power Requirements Based on Micro Light Plates
- authored by
- Olga Casals, Nicolai Markiewicz, Cristian Fabrega, Isabel Gràcia, Carles Cane, Hutomo Suryo Wasisto, Andreas Waag, Joan Daniel Prades
- Abstract
A film of gas sensitive ZnO nanoparticles has been coupled with a low-power micro light plate (μLP) to achieve a NO 2 -parts-per-billion conductometric gas sensor operating at room temperature. In this μLP configuration, an InGaN-based LED (emitting at 455 nm) is integrated at a few hundred nanometers distance from the sensor material, leading to sensor photoactivation with well controlled, uniform, and high irradiance conditions, and very low electrical power needs. The response curves to different NO 2 concentrations as a function of the irradiance displayed a bell-like shape. Responses of 20% to 25 ppb of NO 2 were already observed at irradiances of 5 mWatts·cm -2 (applying an electrical power as low as 30 μW). In the optimum illumination conditions (around 60 mWatts·cm -2 , or 200 μW of electric power), responses of 94% to 25 ppb were achieved, corresponding to a lower detection limit of 1 ppb of NO 2 . Higher irradiance values worsened the sensor response in the parts-per-billion range of NO 2 concentrations. The responses to other gases such as NH 3 , CO, and CH 4 were much smaller, showing a certain selectivity toward NO 2 . The effects of humidity on the sensor response are also discussed.
- External Organisation(s)
-
Universitat de Barcelona
Technische Universität Braunschweig
Autonomous University of Barcelona (UAB)
- Type
- Article
- Journal
- ACS SENSORS
- Volume
- 4
- Pages
- 822-826
- No. of pages
- 5
- ISSN
- 2379-3694
- Publication date
- 26.04.2019
- Publication status
- Published
- Peer reviewed
- Yes
- ASJC Scopus subject areas
- Bioengineering, Instrumentation, Process Chemistry and Technology, Fluid Flow and Transfer Processes
- Electronic version(s)
-
http://hdl.handle.net/2445/130016 (Access:
Open)
https://doi.org/10.1021/acssensors.9b00150 (Access: Closed)
