title: A microfluidic optical platform for real-time monitoring of pH and oxygen in microfluidic bioreactors and organ-on-chip devices.
abstract: 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.
authors.forename: Seyed Ali
authors.initials: SA
authors.lastname: Mousavi Shaegh
authors.forename: Fabio
authors.identifier: 0000-0003-0960-9931
authors.initials: F
authors.lastname: De Ferrari
authors.forename: Yu Shrike
authors.initials: YS
authors.lastname: Zhang
authors.forename: Mahboubeh
authors.initials: M
authors.lastname: Nabavinia
authors.forename: Niema
authors.initials: N
authors.lastname: Binth Mohammad
authors.forename: John
authors.initials: J
authors.lastname: Ryan
authors.forename: Adel
authors.initials: A
authors.lastname: Pourmand
authors.forename: Eleanor
authors.identifier: 0000-0003-3499-8756
authors.initials: E
authors.lastname: Laukaitis
authors.forename: Ramin
authors.initials: R
authors.lastname: Banan Sadeghian
authors.forename: Akhtar
authors.initials: A
authors.lastname: Nadhman
authors.forename: Su Ryon
authors.initials: SR
authors.lastname: Shin
authors.forename: Amir Sanati
authors.initials: AS
authors.lastname: Nezhad
authors.forename: Ali
authors.initials: A
authors.lastname: Khademhosseini
authors.forename: Mehmet Remzi
authors.initials: MR
authors.lastname: Dokmeci