Azimzadeh, MostafaKhashayar, PatriciaAmereh, MeithamTasnim, NishatHoorfar, MinaAkbari, Mohsen2022-11-192022-11-1920212021Azimzadeh, M., Khashavar, P., Amereh, M., Tasnim, N., Hoorfar, M., & Akbari, M. (2021). “Microfluidic-based oxygen (O2) sensors for on-chip monitoring of cell, tissue and organ metabolism.” Biosensors, 12(1), 6. https://doi.org/10.3390/bios12010006https://doi.org/10.3390/bios12010006http://hdl.handle.net/1828/14507Oxygen (O₂) quantification is essential for assessing cell metabolism, and its consumption in cell culture is an important indicator of cell viability. Recent advances in microfluidics have made O₂ sensing a crucial feature for organ-on-chip (OOC) devices for various biomedical applications. OOC O₂ sensors can be categorized, based on their transducer type, into two main groups, optical and electrochemical. In this review, we provide an overview of on-chip O₂ sensors integrated with the OOC devices and evaluate their advantages and disadvantages. Recent innovations in optical O₂ sensors integrated with OOCs are discussed in four main categories: (i) basic luminescence-based sensors; (ii) microparticle-based sensors; (iii) nano-enabled sensors; and (iv) commercial probes and portable devices. Furthermore, we discuss recent advancements in electrochemical sensors in five main categories: (i) novel configurations in Clark-type sensors; (ii) novel materials (e.g., polymers, O₂ scavenging and passivation materials); (iii) nano-enabled electrochemical sensors; (iv) novel designs and fabrication techniques; and (v) commercial and portable electrochemical readouts. Together, this review provides a comprehensive overview of the current advances in the design, fabrication and application of optical and electrochemical O₂ sensors.enoxygen sensorsmicrofluidicsorgan-on-chips (OOCs)on-chip monitoringLaboratory for Innovations in Micro Engineering (LiME)Centre for Advanced Materials and Related Technology (CAMTEC)ArticleDepartment of Mechanical Engineering