Abstract
The integration of electronic sensors into single-use systems for bioprocessing is challenged by their sensitivity to sterilizing γ-irradiation. This challenge also applies to reference electrodes (REs), whose potentials may be destabilized upon ionization and drift over time. Here we evaluate the performance of thin-film Ag/AgCl REs over a two-month window following γ-ray sterilization using a 60Co source. γ-REs display a characteristic voltage decay function ascribed to the dissipation of radiation-induced charge defects, and exhibit long-term potentiometric stability when stored in phosphate-buffered saline (PBS) with a 95% confidence interval of 4 mV over 60 days. γ-REs have a mean insensitivity (inertness) of 0.6 mV/decade in pH buffers (4.5– 9.0) and/decade in the presence of organic solutes and ions at physiological ionic strength. γ-REs paired with thin-film working electrodes (WE) form sensors with near-Nernstian sensitivity, and irradiation of a thin-film pH sensor (γ-pH/WE plus γ-RE) produces a logarithmic voltage decay that is readily corrected by a single-point calibration function. The γ-irradiated sensor can monitor pH changes in sterile cell culture media over a 3-week period and produces readouts with a mean deviation below 0.04 pH units relative to a commercial meter (ground truth).
Date of this Version
8-2-2024
Recommended Citation
Zhao, Bingyuan and Wei, Alexander, "Radiation-tolerant thin-film reference electrodes and potentiometric sensors" (2024). Department of Chemistry Faculty Publications. Paper 31.
https://docs.lib.purdue.edu/chempubs/31
Comments
This is the author-accepted manuscript of of Zhao, B and Wei, A. (2024) Radiation-tolerant thin-film reference electrodes and potentiometric sensors. Sensors and Actuators B: Chemical, 416. Copyright Elsevier, the version of record is available at DOI: 10.1016/j.snb.2024.136058, and it is made available here CC-BY-NC-ND.