Feasibility Analysis

We verified that our initial idea works and that we can actually get a moving GFP band in the channel responding to different input acetaldehyde concentrations. In order our smoColi bacteria to start reporting acetaldehyde in the air (when GFP band appears at the begining of the channel), system should be supplied with around 44.05 mg/L acetaldehyde. In order for the band to be able to form at the very end of the channel, the input acetaldehyde concentration should be 2420 mg/L.

Process Design

After simulating our system in COMSOL, we came to the following conclusions that helped us designing the channel experimentally:

• E. coli can generate a gradient by degrading a substance replenished by diffusion in an agarose-filled channel.
• It can do so within a reasonable experimental timeframe (within several hours).
• It can do so within reasonable channel lengths (several centimeters.
• Channel diameter is irrelevant for our system.
• We need 44.05 mg/L of input acetaldehyde concentration for the band to appear, 2420 mg/L for it to come to the end of the channel.