Third-Party ATP Sensing in Polymersomes: A Label-Free Assay of Enzyme Reactions in Vesicular Compartments


 Umit Hakan Yildiz , Hans-Peter M. De Hoog , Zhikang Fu , Nikodem Tomczak, Atul N. Parikh , Madhavan Nallani , and Bo Liedberg, Small 10, 442–447, 2014


Submicrometer, porous polymeric vesicles, composed of an amphiphilic di-block copolymer, polystyrene-b-polyisocyanoalanine (2-thiophene-3-yl-ethyl) amide, are used to encapsulate an enzyme, alkaline phosphatase, and a fluorescent reporter polymer poly 1(3((4methylthiophen-3-yl)oxy) propyl) quinuclidin-1-ium. Passive diffusion of exogenously added adenosine triphosphate (ATP) through the membrane was sensed by monitoring the ATP-induced fluorescence quenching of the reporter polymer followed by partial recovery of its emission due to hydrolysis of reporter-bound ATP by alkaline phosphatase.

DOI: 10.1002/smll.201300060