Enhanced Green Fluorescent Protein (GFP) fluorescence after polyelectrolyte caging.

Discovery of Green Fluorescent Protein (GFP) constituted an important improvement for living cell studies on submicron resolution allowing in vivo fluorescence labeling. We studied the photo-physical properties of single GFP molecules incorporated in a charged polyelectrolyte environment by means of single molecule spectroscopy. The fluorescence characteristics change dramatically in terms of photo-stability,lifetime and blinking behavior so that the proteins scale up to quantum dots. The reported results highlight interesting applications in the design of fluorescent markers and in the development of optical data storage architectures.