Electrochemical sensing of high density photosynthetic cells using a microfluidic chip

A microfluidic chamber with a micro-sieve was designed to immobilize high density photosynthetic cells in a single layer, and used for measuring the photosynthetic activity of cells with two internal metal electrodes. The PDMS microfluidic chamber was fabricated using soft lithography, and bonded onto a glass substrate with two electrodes micropatterned using a sputter. Cyclic voltammetry measurement was conducted to evaluate the characteristics of the internal electrodes in a redox solution. In the chamber, cells were densely packed in either aqueous or hydrogel environments, and the physiological feature of cells during photosynthesis was analyzed using an amperometric or potentiometric method. A simulation was conducted to estimate the oxygen distribution and generation rate during photosynthesis.