Real-time integrated and multiplexed electrochemical sensor for reactive oxygen species in a high-throughput microphysiological system.

The integration of real-time sensors in microphysiological systems (MPS) faces steep challenges due to the mass transport limitations inherent to microfluidic environments, complex microdevice fabrication methods, and maintenance of long-term performance at high throughput. Reactive oxygen species (ROS) represent attractive yet elusive sensing targets for MPS due to their integral role in cellular metabolism, oxidative homeostasis, and response to disease and injury. Nevertheless, without real-time measurement, their short-lived nature limits practical investigations of ROS as biomarkers in biomedical research. In this work, we have integrated a 96-plex, real-time ROS measurement system into PREDICT96, a high-throughput MPS platform, as a first demonstration of a highly multiplexed electrochemical sensor capability. The ROS measurement system comprises a miniaturized amperometric sensor array capable of rapidly measuring H2O2, a prototypical ROS, at micromolar concentrations (1-10 μM) with high sensitivity and selectivity across 96 microphysiological devices. Integrated microfluidic pumping enables active mixing during measurement and supports the detection of targets with low concentrations or short lifetimes. This novel capability will enable future work investigating ROS as biomarkers for disease modeling and medical countermeasure evaluation, targeting viral respiratory infections of lung-immune tissue models.