PixCell is a major improvement on an existing electrogenetic system, making it aerobic, more responsive and fully modular. The system depends on a complex network of electrochemical, chemical and biomolecular interactions.
Electrochemical Module Design
Redox molecules are maintained in a reduced form in ambient conditions. Application of a +0.5V potential oxidises the redox molecules, allowing for activation of the genetic circuit. Application of a -0.3V potential ensures the redox molecules remain reduced, preventing activation of the genetic circuit.
Potentiostat:
The controller of the system. It generates either a +0.5V (ON) or -0.3V (OFF) current in the electrodes.
Electrode or Electrode Array:
The electrode is the driving force of the system. It allows for oxidation and reduction of redox molecules.
Pyocyanin:
This is a redox-cycling molecule produced by Pseudomonas aeuriginosa. In its oxidised form it can activate gene transcription of redox-signalling pathways, either directly or by oxidative stress. In normal aerobic conditions it is oxidised.
Ferrocyanide/Ferricyanide:
These molecules are well known redox mediators. The oxidised form (ferrocyanide) can draw electrons from the cells quinone pool. This amplifies the activity of redox-cycling molecules like pyocyanin. When the reduced form (ferricyanide) is present the opposite is true.
Sodium Sulfite:
This is an oxygen scavenger as it removes oxygen from solution. This allows for pyocyanin to be maintained in a reduced form but does not diminish GFP fluorescence, suggesting cells remain in aerobic conditions.
