Hydrogel microarray for monitoring of pH and dissolved oxygen in cell culture media

A combined dissolved oxygen and pH sensitive poly(ethylene glycol) hydrogel microarray was fabricated for use in monitoring cell culture media. The sensor was prepared by filling micro-channels with a hydrogel precursor solution containing pH or oxygen sensitive fluorophores. This solution was then cured by passing UV light through a mask placed to the channels, creating array with 100 μm elements. An imaging system with a monochrome CCD camera and appropriate interference filters was used to capture the fluorescence image induced by excitation of microstructure in transmission mode. The sensor performance was characterized in buffer solution (PBS) and cell culture media (MEM) across the biological range of pH (6-8) and dissolved oxygen (3-21%).