Integrated microfluidic device to monitor the cells acidification rate in nanoliter volumes using microfabricated iridium oxide electrodes

摘要

We describe a new approach to measure pH differences in microfluidic devices and demonstrate acidification rate measurements in on-chip cell culture systems with nanoliter wells. We used two miniaturized identical iridium oxide (IrO_x) thin film electrodes (20 x 400 μm~2), one as a quasi-reference electrode in the perfusion channel and the other as a sensing electrode in the cell culture volume. Our results show that we can use two identical miniaturized microfabricated IrO_x electrodes to measure pH differences and to monitor the metabolic activity of cell cultures on chip. Our approach is compatible with microfluidic technologies and allows for the fabrication of sensor arrays in combination with on-chip cell culture devices to implement a high throughput platform to monitor cell culture condition and the metabolic activity of a small number of cells.