Development of an integrated microfluidic platform for dynamic oxygen sensing and delivery in a flowing medium.

This paper describes a platform for real-time sensing of dissolved oxygen in a flowing microfluidic environment using an oxygen-sensitive luminescent dye (platinum octaethylporphyrin ketone) integrated into a micro-oxygenator device. Using a phase-based detection method, the luminescent decay lifetime of the dye was consistent with the linear Stern-Volmer relationship using both gaseous and aqueous samples. Maximum sensor resolution varied between 120-780 ppb across a range of dissolved oxygen (DO) concentrations ranging from 0-42.5 ppm. The sensor was subsequently used to determine the convective mass-transfer characteristics of a multi-layer polydimethylsiloxane (PDMS) microfluidic oxygenator. The membrane-based oxygenator showed excellent agreement with an analytical convection model, and the integrated oxygen sensor was accurate across a wide range of tested flow rates (0.05-5 mL min(-1)). The device is unique for its ease of fabrication and highly flexible configuration, as well as the novel incorporation of oxygen delivery and detection in a single micro-device. Potential applications include tissue engineering, cell culturing, and miniaturized bio-assays that require the delivery and/or detection of precise quantities of oxygen within a microfluidic construct.