Automated electrochemical oxygen sensing using a 3D-printed microfluidic lab-on-a-chip system

Area of Science:

• Biomedical Engineering
• Microfluidics
• Electrochemical Sensing

Background:

• Standard physiological models often fail to replicate in vivo oxygen levels.
• Local generation of reactive oxygen species (ROS) is frequently overlooked in current models.
• Accurate monitoring of dissolved oxygen is critical for understanding physiological and pathological processes.

Purpose of the Study:

• To develop a microfluidic lab-on-a-chip system for precise dissolved oxygen monitoring.
• To integrate electrochemical sensing capabilities for real-time ROS generation, specifically hydrogen peroxide (H2O2).
• To create a tool for validating custom electrodes and controlling oxygen levels in organ-on-chip systems.

Main Methods:

• Fabrication of a microfluidic device using high-resolution 3D printing.
• Integration of electrochemical dissolved oxygen sensors and a commercial optical oxygen sensor.
• Inclusion of a micromixer, bubble-trap, and electrochemical cell with gold/platinum black electrodes.

Main Results:

• Sensitive electrochemical oxygen monitoring with a limit of detection of 11.9 ± 0.3 μM.
• Statistically significant correlation between electrochemical and optical oxygen sensor measurements.
• Successful fabrication of a one-step, integrated microfluidic system.

Conclusions:

• The developed microfluidic system accurately monitors physiological oxygen concentrations and generates H2O2.
• This technology offers a valuable tool for characterizing electrodes and validating sensor performance.
• The system holds potential for real-time regulation of oxygen and ROS in advanced organ-on-chip models.