Fabrication of Core-Shell Bio-Nanocomposites via Biomimetic Mineralization of Metal Organic Frameworks

Biomineralization is one of the nature-owned masteries that the organisms have exploited for millions of years to produce organic-inorganic hybrid materials with highly customized compositions, microstructures, morphologies and functionalities. An emerging field called biomimetic mineralization arose from the idea of employing proteinaceous templates to fabricate novel biochemical composites that cannot be produced in nature. Among various biomimetic mineralization strategies, the core-shell fashioned fabrications are of great interest, due to mineralized shells serving as exoskeleton to protect inlaid biological specimens from external stresses. In addition, biomimetically mineralized shells are also functional materials that can be used for sensing, catalysis and drug delivery.

Metal organic frameworks (MOFs) are a family of porous coordination complexes that possess a high surface area and well-defined porosity. The broad variety of composition, synthetic methods, and physicochemical properties make MOFs to be versatile functional materials. This dissertation summarizes exploration of fabricating core-shell fashioned biology@MOF bio-nanocomposites using the tobacco mosaic virus (TMV) and Escherichia coli (E. coli) as model biological templates. Zeolitic imidazolate framework-8 (ZIF-8), a widely studied MOF member that is featured in robust chemical and thermal stability, was chosen to compose the biomimetically mineralized shells. This dissertation will demonstrate i) success fabrication of TMV@ZIF-8 and E. coli@ZIF-8 core-shell bio-nanocomposites; ii) mechanistic understanding in regard to the impacts of synthetic conditions on morphology, crystallinity and stability of resultant products; iii) impact of synthetic conditions on cell viability.