PHAIR – A biosensor for pH measurement in air-liquid interface

Abstract

1AbstractIn many biological systems, pH can be used as a parameter to understand and study cell dynamics. However, measuring pH in live cell culture is limited by the sensor ion specificity, proximity to the cell surface, and scalability. Commercially available pH sensors are difficult to integrate into a small-scale cell culture system due to their size and are not cost-effective for disposable use. We made PHAIR - a new pH sensor that uses a micro-wire format to measure pH in vitro human airway cell culture. Tungsten micro-wires were used as the working electrodes, and silver micro-wires with a silver/silver chloride coating were used as a pseudo reference electrode. pH sensitivity, in a wide and narrow range, and stability of these sensors were tested in common standard buffer solutions as well as in culture media of human airway epithelial cells grown at the air-liquid interface in a 24 well cell culture plate. When measuring the pH of cells grown under basal and challenging conditions using PHAIR, cell viability and cytokine responses were not affected. Our results confirm that micro-wires-based sensors have the capacity for miniaturization, and detection of diverse ions while maintaining sensitivity. This suggests the broad application of PHAIR in various biological experimental settings.

Liquid Metal pH Morphology Sensor Used for Biological Microenvironment Detection

“…Studying cell growth, development patterns, and functions in vitro by culturing cells in a simulated vivo environment is an important tool in modern life sciences, and pH detection is of great value in the cellular microenvironment. 1,2 Hydrogen ion, which directly reflects the pH of the cellular microenvironment, plays an important role in cell growth, development, and division. 3,4 In general, the pH of the cellular environment is dynamically balanced within a range of 7−9, while the pH of cancer cells can reach 5.5.…”