A microfluidic optical platform for real-time monitoring of pH and oxygen in microfluidic bioreactors and organ-on-chip devices

• Published in: Biomicrofluidics Vol. 10; no. 4; pp. 044111 - 44124
• Main Authors: Mousavi Shaegh, Seyed Ali, De Ferrari, Fabio, Zhang, Yu Shrike, Nabavinia, Mahboubeh, Binth Mohammad, Niema, Ryan, John, Pourmand, Adel, Laukaitis, Eleanor, Banan Sadeghian, Ramin, Nadhman, Akhtar, Shin, Su Ryon, Nezhad, Amir Sanati, Khademhosseini, Ali, Dokmeci, Mehmet Remzi
• Format: Journal Article
• Language: English
• Published: United States American Institute of Physics 01.07.2016; AIP Publishing LLC
• Subjects: Bioreactors; Construction costs; Design modifications; Detection; Electro-optics; Fibroblasts; Low cost; Luminous intensity; Monitoring; Optical communication; Organic light emitting diodes; Oxygen; Photodiodes; Regular; Sensors
• ISSN: 1932-1058; 1932-1058
• DOI: 10.1063/1.4955155

There is a growing interest to develop microfluidic bioreactors and organ-on-chip platforms with integrated sensors to monitor their physicochemical properties and to maintain a well-controlled microenvironment for cultured organoids. Conventional sensing devices cannot be easily integrated with microfluidic organ-on-chip systems with low-volume bioreactors for continual monitoring. This paper reports on the development of a multi-analyte optical sensing module for dynamic measurements of pH and dissolved oxygen levels in the culture medium. The sensing system was constructed using low-cost electro-optics including light-emitting diodes and silicon photodiodes. The sensing module includes an optically transparent window for measuring light intensity, and the module could be connected directly to a perfusion bioreactor without any specific modifications to the microfluidic device design. A compact, user-friendly, and low-cost electronic interface was developed to control the optical transducer and signal acquisition from photodiodes. The platform enabled convenient integration of the optical sensing module with a microfluidic bioreactor. Human dermal fibroblasts were cultivated in the bioreactor, and the values of pH and dissolved oxygen levels in the flowing culture medium were measured continuously for up to 3 days. Our integrated microfluidic system provides a new analytical platform with ease of fabrication and operation, which can be adapted for applications in various microfluidic cell culture and organ-on-chip devices.