Microfluidic free-flow electrophoresis chips with an integrated fluorescent sensor layer for real time pH imaging in isoelectric focusing.

Functional microfluidic free-flow electrophoresis chips with integrated fluorescent pH sensors are presented. Polyethylene glycol based structures were fabricated that allowed for integration of both functions on a single microchip. Microchips were applied in free-flow isoelectric focusing of model compounds and proteins with on-line monitoring of pH during microscale electrophoretic separation.