Long-term viability of photosynthetic cells stacked in a hydrogel film within a polydimethylsiloxane microfluidic device

Abstract

Immobilizing cells while maintaining their long-term viability is important to utilize cells in biosensors and energy devices. In this study, we fabricated a hydrogel film of 10 μm thickness immobilizing photosynthetic cells, using a polydimethylsiloxane microfluidic device, and we monitored the viability of the cells for 30 days. Cell viability was measured by chronoamperometry using two electrodes located in the microfluidic device and was compared between hydrogel-immobilized and non-immobilized cells. The non-immobilized cells showed variation in viability. In contrast, the hydrogel-immobilized cells remained viable for 30 days. A simulation of the oxygen distribution changes by photosynthesis of the cells and mass transfer of cell culture nutrients (NaNO3) suggested that a proper environment for cell survival was effectively established inside the hydrogel. We successfully fabricated a photosynthetic cell-laden hydrogel with potential use in next-generation photosynthesis-based solar cells and sensors.