By appropriate substitution, polyoxometalates (POMs) can be modified to be organic-inorganic supramolecules (OISMs) that are nonaqueous or water soluble and form aggregates in solution. Here, we report a new OISM, (TBA)3POM-PPCT, that can self-assemble to form bilayer vesicles controlled by Eu3+ in nonaqueous solution. Dynamic light scattering, transmission and scanning electron microscopy techniques, and atomic force microscopy clearly demonstrated the controllable formation of stable bilayer vesicles with an average hydrodynamic radius of about 510 nm. Because of the coordination between (TBA)3POM-PPCT and Eu3+, the stable vesicles possess fluorescence, determined by studying fluorescence spectra, and show highly selective response to Cu2+, allowing them to function as an ion-detecting platform to Cu2+.