(Project 4 - Hilt, Dziubla) Due to their relative chemical stability and pervasive contamination of the environment, chlorinated organics such as polychlorinated biphenyls (PCBs) pose serious risks to human health. Given the lack of highly reliable rapid screening tools, a convincing evidence base supports study of biological binding domains as a viable strategy for advances in PCB detection. Specifically, novel nanomaterials will be developed and will result in a platform technology that allows for the inclusion of biomimetic domains into a variety of system designs, facilitating the rapid detection of PCB congeners in the ppm levels needed for useful screening. Furthermore, the biomimetic polymer coatings on the magnetic nanoparticles will allow for capture, analysis, remediation, and release on demand. Despite a production ban in 1979 and decades of remediation efforts, PCBs remain a persistent environmental contaminant. Gas chromatography mass spectrometry (GC-MS) remains the current standard for sensitivity and specificity in detecting PCBs in the environment. However, GC-MS requires intricate, time-consuming extraction and sample purification techniques. It has been reported that the binding domains of PCB-specific antibodies (e.g., S2B1) form sterically constrained, highly aromatic (e.g., tryptophan, tyrosine) pockets, allowing for pi-pi bond stacking interactions. These same environments can also be seen in tests of PCB soil distribution (e.g., humin containing matter) and biodistribution (e.g., lipid rafts, PCB-binding proteins). We hypothesize that synthetic, biomimetic PCB-binding domains can be synthesized by incorporating phenolic and related moieties into polymeric coatings. In preliminary studies, we showed that PCB binding was increased through the incorporation of phenolic moieties in our polymeric coatings. The overall goal of this project is to develop a magnetic nanocomposite platform that allows for the selective capture of PCB congeners with a range of affinities and selectivities.
The specific aims follow: (1) synthesize and characterize physicochemical properties of magnetic nanocomposites (i.e., biomimetic polymeric networks coated on the surface of magnetic nanoparticles) with the ability to capture/release or capture/sense PCB congeners with tunable affinity and selectivity; (2) characterize the functionality of synthesized nanomaterials, including binding, capture/release, and fluorescence sensing analysis; and (3) apply these novel nanomaterials for the selective capture and sensing of PCBs and mixtures, including coplanar, non-coplanar, and mixed congener PCBs and mixtures (e.g. PCBs 126, 153, 118). The coatings will be engineered to have precise nanoscale thickness, tunable affinity/selectivity and reversible binding using surface initiated polymerizations, incorporating phenolic moieties and applying molecular imprinting approaches. These nanomaterials will have broader impact through their potential application in remediation and biomedical applications.
The selective capture and sensing of PCBs is critical for understanding environmental contamination by this class of toxic compounds and its impact on human health. The novel nanomaterials developed in this work will provide a solution to the problem widespread contamination at Superfund sites which poses serious global environmental health challenges. Addressing this fundamental research problem will directly impact disease prevention efforts.
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