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 optoelectronic properties are directly related with their structural organization and therefore intra and/or interpolymeric pi-pi stacking affects the charge transport and energy transfer processes occurring in the devices. The characterization of luminescent films at the solid-liquid interface will be very important to establish a relationship between the photoluminescence properties and morphology of the materials. The NR data on a PEDOT:PSS(with ethyleno glycol, EG)-Si substrate will allow us to mimic a sensor where EG-PEDOT:PSS works as an electrode, a polyfluorene derivative bearing aza-crown pendent groups as an active layer, and sodium dodecyl sulfate surfactant as a model molecule for an analyte.