Surface functionalization of recyclable polymer for application as a flexible fluorescent sensor

The use of surface-functionalized polymers has shown great potential for application, emphasizing the development of flexible optoelectronic devices (FOD). There are several ways to carry out this functionalization, attributing different characteristics to the resulting material. In the present study, polyethylene terephthalate (PET) films were surface-functionalized with [4-(2-hydroxy naphthyl)diazenyl] benzoic acid using UV radiation and the direct grafting method. The resulting films were characterized using different techniques, which enabled the identification of functional groups characteristic of the compound azo, thus proving that both methods used for surface functionalization were efficient. Subsequently, the sensing capabilities of these films were evaluated by being exposed to solutions of different cations. The fluorescence signal was the measurable response, in which its variation is dependent on the interaction of analytes with the functionalized surface of the PET film. The main advantages observed in this study are simplicity, low cost and the possibility of using recycled polymer, contributing to sustainable development and environmental conservation.