Water-soluble conjugated polymers (WSCP) are an important class of materials which have received great attention as active materials in optoelectronic devices and in biosensing. The incorporation of the crown moieties into the polymer structure brings many advantages for the development of new sensing platforms. Crown compounds have been shown to selectively interact with cations. It is well known that the aggregation behaviour of WSCP in solution and in film is very complex. The formation of highly ordered supramolecular self-assembled structures is very important to attain a better morphology and optimise the performance of the device. This is possible through the formation of WSCP-surfactant complexes. The characterization of mesostructures in WSCP(surfactant) system in film is crucial to establish a correlation between the photophysical properties of the material and its morphology.