Broadband Dielectric Spectroscopic Detection of Ethanol: A Side-by-Side Comparison of ZnO and HKUST-1 MOFs as Sensing Media

Published

June 25, 2022

Author(s)

Papa Amoah, Pentao Lin, Zeinab Mohammed Hassan, Rhonda Franklin, Engelbert Redel, Helmut Baumgart, Yaw S. Obeng

Abstract

Changes in the chemo-electrical intrinsic properties of metal-oxide materials (MO) are commonly used as the basis of gas sensors. The most common gas sensors are based on chemically induced changes in electrical resistivity which necessarily involve making electrical contacts to the sensing materials. These contacts introduce errors into the measurements, mostly from the parasitic errors in imperfect contacts. In this paper we revisit the use of radio frequency (RF) alternate metrology. Specifically, we have leveraged thermal- and chemical-induced changes in RF propagation characteristics (i.e., S-parameters) to compare ZnO and metal-organic-framework (MOF, i.e. HKUST-1; Hong Kong University of Science and Technology-1) sensing material at temperatures under 100 °C. We show that the technique can detect ethanol, a typical volatile organic compound, at relatively low temperatures, as well as afford new mechanistic insights that are inaccessible with the traditional resistance-based measurements.

Citation

Chemsensors

Volume

10

Issue

7

Pub Type

Journals

Download Paper

https://doi.org/10.3390/chemosensors10070241

Local Download

Keywords

Broadband Dielectric spectroscopy, microwave, sensor volatile organic compounds, dielectric

Citation

Amoah, P. , Lin, P. , Hassan, Z. , Franklin, R. , Redel, E. , Baumgart, H. and Obeng, Y. (2022), Broadband Dielectric Spectroscopic Detection of Ethanol: A Side-by-Side Comparison of ZnO and HKUST-1 MOFs as Sensing Media, Chemsensors, [online], https://doi.org/10.3390/chemosensors10070241 , https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=933074 (Accessed October 9, 2025)