Multimodal Magnetic and Luminescent Nanomaterials for Biomedical and Data Storage Applications

Abstract

Multimodal nanomaterials integrate complementary chemical, optical, and physical functionalities into a single nanoscale object, and have potential applications in numerous fields. With a range of optoelectronic properties and a versatile surface chemistry, transition metal chalcogenide nanomaterials are ideal multimodal platforms. In this thesis, colloidal CdSe-based quantum dot nanocrystals and 2H-MoS2 nanosheets were functionalised with thiolated paramagnetic and luminescent species in view of bio-imaging and data processing applications. Firstly, fluorescent CdSe/CdS/ZnS quantum dots were functionalised with a paramagnetic Gd3+ magnetic resonance contrast agent, with the resulting hybrid material displaying an exceptionally high relaxivity per nanoparticle. Secondly, liquid-exfoliated 2H-MoS2 nanosheets were covalently functionalised simultaneously with Eu3+ and Gd3+ complexes. The luminescent and paramagnetic properties of both component lanthanides were maintained post-functionalization, in addition to the semiconductor 2H-MoS2 phase. This work represents the first example of lanthanide complexes being covalently linked to MoS2 nanosheets. Lastly, monofunctionalised {Cr7Ni} molecular nanomagnet rings were grafted to the surface of CdSe/ZnS quantum dots, and retained both the bright optical emission of the quantum dots, and the S = ½ qubit ground state of the {Cr7Ni} rings. This is the first example of nanomagnet functionalised quantum dots, and future studies will investigate photoswitchable quantum dot/qubit hybrids.

Date of Award	1 Aug 2018
Original language	English
Awarding Institution	The University of Manchester
Supervisor	O'Brien (Supervisor) & Floriana Tuna (Supervisor)