FIGURE 7.

Sensor Robustness. CO₂ sensor performance in 2 L bioreactor was validated against an offline CO₂ analyzer prior to autoclave sterilization (A), and after autoclave sterilization (B). Sensor performance was monitored while sparging up to 20 kPa CO₂ into the reactor (temporally represented by shaded gray region), then CO₂ levels were allowed to return to baseline levels before repeating. Performance before and after autoclaving is nominally indistinguishable; performance does not appear to be altered by steam sterilization, as expected from the robust physical properties PDMS. Multiple sensors were tested before and after autoclaving without alterations in sensing performance; data shown is representative of multiple experiments. (C) The CO₂ sensor is also shelf stable for long periods of time. Sensor spectra was monitored after exposure to 100% CO₂ beginning the day of fabrication with minimal shift in performance observed.