Figure 2.
Characterization of the oxygen diffusion in the device over time for devices containing a PMMA sheet (circle symbols) or only PDMS (square symbols), for three independent devices for each case on three different days. Data are presented as the oxygen tension as a function of time, this being assessed by monitoring the decrease in the fluorescence intensity of the tris(2,2′-bipyridyl)dichlororuthenium(II) hexahydrate (Ru(BPY)3) oxygen-sensitive probe added in aqueous solution in the device. Data were acquired over a period of more than 4 h, as detailed in the experimental section and analyzed as explained in supplementary material S2.