Synthesis, characterisation and biofunctionalisation of magnetoelectric nanoparticles for biomedical application

磁电纳米粒子是同时具有铁磁性和铁电性的纳米粒子。这两种性质之间的耦合是重要的，因为它有助于直接控制铁电性或铁磁性。尽管有几种实现磁电效应的方法，但由于大的磁电效应，近年来将铁磁材料与铁电材料组合在核-壳纳米结构中已经获得了显著的兴趣。本研究中使用的磁性纳米粒子将钴铁氧体由于其高磁致伸缩系数和铁电相将钛酸钡由于其高压电系数的合成和控制其尺寸和形貌是至关重要的在生物医学应用中的纳米粒子的性能取决于这些变量。纳米颗粒的流体动力学尺寸影响诸如血管中的纳米颗粒浓度分布的因素，影响纳米颗粒从循环中的清除，并且影响纳米颗粒从脉管系统中的渗透性。类似地，形状影响纳米颗粒循环时间，与球形纳米颗粒相比，各向异性NP如具有更高纵横比的棒状NP具有更长的循环时间和更高的生物利用度。此外，在MENP的情况下，也是磁相和电相之间的耦合取决于尺寸和形态。由于MENP用于生物医学应用是一个最近新兴的领域，因此当前MENP发展的障碍是具有可调尺寸和形态且也可以重现的MENP的受控合成。沿着电磁纳米粒子的合成，表征电磁纳米粒子的性质对评价其性能至关重要。技术，如X射线衍射纯度分析，透射发射显微镜的大小和形态分析，动态光散射的流体动力学大小的研究，红外光谱的表面组成研究，超导量子干涉装置的磁性，修改后的扫描探针显微镜的磁电特性等将在我的研究中使用。最后，合成的MENP将被功能化用于特定的生物医学应用。总之，我的研究重点是研究MENP的形状和尺寸对界面处电相和磁相耦合的影响，以及其在生物医学应用中的新功能，如靶向药物递送。

Magnetoelectric nanoparticles (MENP) are nanoparticles that can exhibit ferromagnetism and ferroelectricity simultaneously. The coupling between the two properties is significant because it facilitates a direct control of ferroelectricity or ferromagnetism. Although, there are several ways of achieving magnetoelectric effect, combining a ferromagnetic material with a ferroelectric material in a core-shell nanostructure has gained significant interest in recent years due to large magnetoelectric effects. The magnetic nanoparticle used in this study will be cobalt ferrite due to its high magneto strictive coefficient and the ferroelectric phase will be barium titanate due to its high piezoelectric coefficient.The synthesis of monodisperse MENP and control of its size and morphology is of vital importance in biomedical application as the properties of nanoparticles are dependent on these variables. The hydrodynamic size of nanoparticles affects factors such as nanoparticle concentration profile in a blood vessel, affects nanoparticle clearance from circulation, and affects the permeability of nanoparticles out of the vasculature. Similarly, the shape affects nanoparticles circulating time with anisotropic NP like rod shape NP with higher aspect ratio having longer circulation time and higher bioavailability compared to spherical nanoparticles. Furthermore, in the case of MENP, it is also the coupling between the magnetic and electric phases that is dependent on size and morphology. As MENP for biomedical application is a recently emerging field, the current roadblock in the advancement of MENP is the controlled synthesis of MENP with tuneable size and morphology that can also be reproducible. Along with the synthesis, characterisation of MENP is vital to evaluate their properties. Techniques such as X-ray Diffraction for purity analysis, Transmission Emission Microscopy for size and morphology analysis, Dynamic Light Scattering for hydrodynamic size study, Infrared Spectroscopy for surface composition study, Superconducting Quantum Interference Device for magnetic properties, a modified Scanning Probe Microscope for magnetoelectric characterisation among others will be utilised in my research. Finally, the synthesised MENP will be functionalised for specific biomedical application. To conclude, my research focuses on studying the shape and size effect of MENP on the coupling of electric and magnetic phases at the interface and its new functionalities for biomedical applications such as targeted drug delivery.