Fluorescent and “breathable” CO2 responsive vesicles inspired from green fluorescent protein

The design of green fluorescent protein (GFP) chromophore labeled, CO2 responsive vesicles that can mimic the breathing of jellyfish is described. The vesicles were obtained via the self-assembly of a di-block copolymer bearing a hydrophilic poly(ethylene glycol) (PEG) segment and a hydrophobic, CO2 responsive poly((diethylamino)ethyl methacrylate) (PDEAEMA) segment, with a GFP chromophore between the two blocks. Like the breathing of a jellyfish, the vesicles’ size and fluorescence changed significantly upon exposure to CO2, as confirmed by morphology observation and fluorescence measurements. Further analysis suggested that the “breathing” of the vesicles is reversible under a continuous CO2/N2 gas flow. The “breathing” behavior of the fluorescent vesicles was also directly observable under a confocal microscope.