Kaufman Daniel, Winkler Steffen, Heuer Christopher, Shibli Ahed, Snezhko Alexander, Livshits Gideon I, Bahnemann Janina, Ben-Yoav Hadar
Nanobioelectronics Laboratory (NBEL), Department of Biomedical Engineering, Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, 8410501 Beer Sheva, Israel.
Institute of Physics, University of Augsburg, Universitätsstraße 1, 86159 Augsburg, Germany.
Lab Chip. 2025 Mar 11;25(6):1404-1415. doi: 10.1039/d4lc00962b.
Dissolved oxygen is crucial for metabolism, growth, and other complex physiological and pathological processes; however, standard physiological models (such as organ-on-chip systems) often use ambient oxygen levels, which do not reflect the lower levels that are typically found . Additionally, the local generation of reactive oxygen species (ROS; a key factor in physiological systems) is often overlooked in biology-mimicking models. Here, we present a microfluidic system that integrates electrochemical dissolved oxygen sensors with lab-on-a-chip technology to monitor the physiological oxygen concentrations and generate hydrogen peroxide (HO; a specific ROS). This microfluidic lab-on-a-chip system was fabricated using high-resolution 3D printing technology in a one-step process. It incorporates a micromixer, an on-chip bubble-trap, an electrochemical cell with fabricated gold or platinum black-coated working electrodes as well as an Ag/AgCl reference electrode, and a commercial optical oxygen sensor for validation. This device enables an automated variation of the oxygen levels as well as sensitive electrochemical oxygen monitoring (limit of detection = 11.9 ± 0.3 μM), with a statistically significant correlation with the optical sensor. The proposed system can serve as a tool to characterize and evaluate custom-made electrodes. Indeed, we envision that in the future it will be used to regulate dissolved oxygen levels and oxygen species in real time in organ-on-chip systems.
