P2.9.12 A Cross-Platform Investigation of Hg-Au Response Profiles

Event

14th International Meeting on Chemical Sensors - IMCS 2012
2012-05-20 - 2012-05-23
Nürnberg/Nuremberg, Germany

Chapter

P2.9 Technology and Application

Author(s)

M. Griffin, S. Ippolito, Y. Sabri, S. Bhargava - Advanced Materials & Industrial Chemistry, School of Applied Sciences, RMIT University (Australia), K. Kalantar-zadeh, G. Matthews - Microelectronics and Materials Technology Centre, RMIT University (Australia)

Pages

1731 - 1734

DOI

10.5162/IMCS2012/P2.9.12

ISBN

978-3-9813484-2-2

Price

free

Abstract

The amalgamation of elemental mercury (Hg) with gold (Au) thin-films is a commonly utilized mechanism for sensing Hg vapor in air. In this work, we investigate and compare the sensing mechanisms of a resistive based sensor and a quartz crystal microbalance (QCM) which both employ an Au thin-film sensitive layer which was deposited under identical conditions. Both sensors were tested concurrently at several operating temperatures ranging between 30 and 130°C. Contrary to models described in the literature, which suggests that the response profile should be independent of sensing platforms, this work clearly shows that the mechanisms are different for the two tested platforms. The QCM is shown to primarily respond to the surface bound Hg, including Hg-Hg bonds, whereas the resistive wheatstone-bridge device primarily responds to Hg diffused into the Au sensitive layer, resulting in different transient responses for the same Hg concentration under identical conditions for each sensor platform.