Inorganic Species-Doped Polypropylene Nanoparticles for Multifunctional Detection

Plastic debris accounts for the most substantial part of marine pollution and its degradation byproducts are omnipresent. Beyond representing a serious potential hazard for the marine ecosystem, micro- and nanoplastics may easily enter the human food chain with effects on health that are still poorly understood and undefined. In particular, while polypropylene (PP) is amongst the most commonly detected plastic fragments, studies to evaluate its traceability and role in food chain are still very limited mainly due to a lack of easy synthesis routes for model PP micro- and nanoparticles. In this work, we have developed a protocol for high-throughput production of PP nanoparticles in the size range 80–350 nm, via the oil-in-water emulsion technique in the presence of the sodium cholate bile salt as a nonhazardous surfactant. In addition, the traceability of PP has been achieved by introducing selected markers into PP nanoparticles containing inorganic metals and/or fluorescent dyes such as plasmonic ultrasmall gold nanoparticles, quantum dots, and/or luminescent dyes. Moreover, PP nanoparticles are stable in an aqueous environment due to the biocompatible surfactant and enable the detection by multiple techniques, thanks to their modulable core. Therefore, they represent a significant advance in the development of model plastic nanomaterials for different applications, which might include toxicity and biodistribution studies.