Designing Sensitivity—A Comparative Analysis of Microelectrode Topologies for Dissolved Oxygen Sensing

The monitoring of dissolved oxygen is a key parameter in many fields, namely the treatment and monitoring of various cerebral traumas. Leveraging complementary metal oxide semiconductor (CMOS) manufacturing techniques and biocompatible electrolyte polymers, electrochemical sensors hold the potential for compact, simple, and scalable point-of-care dissolved oxygen sensors. We present here a discussion of guiding microelectrode design principles based on a characterization comparison study conducted across multiple Clark sensors with varying microelectrode geometries. Geometries were covered with a biocompatible Nafion polymer membrane. Polarographic sweeps were conducted on various microelectrode topologies while monitoring devices’ sensing current responses across a 50.3mmHg change in dissolved oxygen in deionized aqueous solution. An optimum design with a ~7-fold improvement in sensitivity was achieved and the results validated with theory.