A CO2-switchable polymer brush for reversible capture and release of proteins

We report on a polymer brush that can be switched between extended (hydrated) and collapsed (dehydrated) chain conformational states just by passing CO2 and an inert gas like N-2 in solution alternately. This conformational change allows for reversible adsorption and release of a protein. In contrast to adding acids and bases for pH change, using gases as the trigger makes it possible to repeat the switching cycle many times without salt accumulation.