Abstract
One of the most studied fields of modern material chemistry concerns the elaboration of functional nanomaterials reserved for a wide range of applications. For several years, researchers have been particularly attracted by the design of multifunctional systems combining in a single system the properties of different materials and exhibiting diverse physical responses when subjected to various stimuli. This work describes the combination of both optical properties of gold and magnetic properties of coordination polymers such as Prussian Blue analogous to form magneto-optical nano-heterostructures presenting an intricate core-shell architecture.Firstly, we have synthesized a series of Prussian Blue Analogous nanoparticles such as Ni3[Fe(CN)6]2 presenting different and controlled sizes, in order to better understand the evolution of their characteristics upon the size reduction from the micro- to the nanoscale.Secondly, we focalized on the design of heterostructured nano-objects composed by a gold core coated with a uniform K+/Ni2+/[FeII(CN)6]4- Prussian Blue analogous shell based on a new and rational approach. These core-shell Au@K+/Ni2+/[FeII(CN)6]4- nanoparticles exhibit both optical properties of the gold core and paramagnetic properties originating from the cyano-bridged coordination polymer layer. Using several techniques, we have investigated the growing mechanism of such intricate system. The optical responses of these nanoparticles can be modulated by controlling the gold core size and the Prussian Blue analogous shell thickness by modifying the experimental parameters. Then we extended the used synthetic approach to other gold core containing heterostructures with K+/Co2+/[FeII(CN)6]4- shell. We have also investigated an original way to design hollow nanoparticles by etching the gold core.The implement of different magnetic behavior, such as ferromagnetism or superparamagnetism, can be achieved by the subsequent growing of a new Prussian Blue Analogous shell on the Au@K+/Ni2+/[FeII(CN)6]4- nanoparticles. In this aim, several Prussian Blue analogous were selected to form the second layer. These double-layered nanoparticles exhibit optical properties originating from the gold core. Additionally, ferromagnetic properties have been successively implemented, proving the multifonctionality of these nano-objects. Particularly, a study on the evolution of the magnetic properties according to the shell thickness of the Prussian Blue analogous was performed on a series of different–sized Au@K+/Ni2+/[FeII(CN)6]4-@K+/Ni2+/[CrIII(CN)6]3- nanoparticles in order to demonstrate the influence of the core-shell architecture on the nature of the magnetic properties.Finally, we evaluated the potential of these nanoparticles for the medical imaging by scintigraphy. Simple Prussian Blue and core-shell Au@K+/Ni2+/[FeII(CN)6]4-@K+/Fe3+/[FeII(CN)6]3- nanoparticles were synthesized and post-synthetically grafted by organic molecules (commercial dextran, biopolymers or lipidic bilayer) to ensure their dispersibility in aqueous media. These nanoparticles have been loaded by radioactive 201Tl+ ions in order to investigate their behavior in the living organism by using SPECT-CT tomography in vivo and establish the influence of the nanoparticles composition, the morphology and the functionalization on the nanoparticles biodistribution and kinetic.