Planar Array Redox Cells
and pH Sensors for
ISS Water Quality and Microbe Detection
M.G. Buehler1, G. M. Kuhlman1 , N.V. Myung, D. Keymeulen1, S. P. Kounaves2, D. Newman3, and D. Lies3
1. Jet Propulsion Laboratory
2. Department of Chemistry.
Tufts University
3. Department
of Geological & Planetary Sciences, California Institute of Technology
Abstract
This Paper describes results acquired from E-Tongue 2 and E-tongue 3 which are arrays of planar three-element electrochemical cells and pH sensors. The approach uses ASV (Anodic Stripping Voltammetry) to achieve a detection limit, which in the case of Pb, is below one µM and which is needed for water quality measurements. The richness of the detectable species is illustrated with Fe where seven species are identified using the Pourbiax diagram. The detection of multiple species is illustrated using Pb and Cu. The apparatus was used to detect the electroactivity of the metabolic surrogate, PMS(phenazine-methosulphate). Finally, four types of pH sensors were fabricated and characterized for linearity, sensitivity, and responsiveness.