stimuli-responsive pamam dendritic macromolecules for optical detection of food spoilage

A new category of smart dendritic structure was synthesized by functionalization of poly(amidoamine) (pamam) dendrimer with spiropyran molecules to afford photoluminescent dendritic structure (sp-pamam). smart optical sensors were prepared by physical incorporation of oxazolidine molecule (ox) in the sp-pamam structure. investigation of optical properties demonstrated photoinduced electron transfer (pet) between spiropyran end group of sp-pamam and oxazolidine molecule. the ph-responsivity of smart macromolecules was used for designing a paper-based ph indicator for visual detection of spoilage in food industry, especially in the case of milk. the prepared papers applied on cap of the milk bottles where a red fluorescence emission was observed after milk spoilage by adsorption of acidic volatile components generated by bacterial degradation and oxidation process on the paper surface.