Microfluidic-Based Oxygen (O2) Sensors for On-Chip Monitoring of Cell, Tissue and Organ Metabolism

Abstract

Oxygen (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.

Integrated biosensors for monitoring microphysiological systems

“…[80][81][82][83][84] For example, fluorescence biosensors that detect hydrogen peroxide or reactive oxygen species (ROS) have been developed to monitor cellular metabolism and processes. 85,86 Total internal reflection fluorescence microscopy has a spatial resolution below 100 nm, providing real-time single-molecule imaging of Fzd8 and Lrp6 in human colon organoid models. 87 Another common fluorescence sensor is based on the Förster resonance energy transfer (FRET).…”

Thin-Film-Based Multifunctional System for Optical Detection and Thermal Treatment of Biological Samples

“…The ability of the proposed platform to perform simultaneously thermal treatments and optical stimulations and monitoring open the doors to several other activities. For example, typical applications that require both heating and optical performances are the cell and bacteria culture processes [ 101 , 102 , 103 , 104 ]. Indeed, there is an increasing interest in performing robust and efficient on-chip cell cultures, that can in turn led to more elaborated analysis, like quality evaluation, drug resistance, electropermeabilization, and so on [ 105 , 106 , 107 , 108 , 109 ].…”

Oxygen gradients dictate angiogenesis but not barriergenesis in a 3D brain microvascular model

“…An important component of oxygen tension models is the prediction of cellular oxygen consumption, which serves as a major sink in the diffusive constitutive equation. There has been substantial innovation in systems to directly measure cellular oxygen consumption including microfluidic‐based approaches (Azimzadeh et al, 2021). Accurate measurements of oxygen consumption are vital to informing computational models of oxygen diffusion within in vitro systems, and previous studies have provided measurements of oxygen consumption by cerebral endothelial cells in culture (McDonald et al, 2019; Rellick et al, 2016; Sheikh et al, 2020).…”