RT Dissertation/Thesis
T1 Development of optically detected magnetic resonance techniques for intracellular magnetic and temperature sensing
T2 Desarrollo de técnicas de resonancia magnética ópticamente detectada para detección intracelular magnética y de temperatura
A1 Cruz Camarneiro, Filipe Miguel
AB Quantum computing and quantum sensing are technologies of the second quantum revolution occurring during our lifetime. The research developed in this thesis is focused on the latter as it explores the quantum metrology capabilities of Nitrogen-Vacancy (NV) centers in diamond. The unique NV defect is composed of a vacancy and a neighboring nitrogen atom in the crystal lattice, forming a single spin system. The NV center sensing properties are attributed to its spin that is susceptible to external physical properties such as magnetic fields and temperature and, more importantly, can be optically manipulated and read out. Within the framework of this thesis, the exploration and application of such a system in the biomedical context is enabled by the development of two live cell compatible setups with Optically Detected Magnetic Resonance (ODMR) capabilities. A confocal setup with both ODMR and Fluorescence Lifetime Imaging Microscopy (FLIM) functionalities and a Widefield/ Total Internal Reflection Fluorescence (TIRF) microscope. The sensitivities ofdistinct diamond photonic platforms for both magnetic field and temperature sensing are determined.The capabilities of NV centers to measure magnetic fields with nanoscale resolution are employed to explore the remanent magnetization of nanoparticle aggregates fabricated for magnetic hyperthermia-based cancer therapy. Magnetic nanoparticles aggregates are deposited on top of bulk diamonds with a shallow implanted NV center layer and the ODMR read out allows reconstructing magnetic field maps at high spatial resolution down to 500 nm.While a multitude of intracellular thermometers based on fluorescence responses have been proposed, the ideal thermometer has yet to be developed. In this thesis, fluorescence lifetime parameters of photostable nanodiamonds are identified as a reliable nanothermometer allowing temperature mapping across cells. This methodology is for the first time successfully deployed in intracellular environments to monitor temperature shifts during optical hyperthermia treatments using plasmonic nanorods in a silica shell as local heat sources.Further, the research performed in this thesis takes a step into applying nanodiamonds in neuroscience  research. With the long-term goal of recording communication patterns between neuronal cells via the detection of magnetic field variations created by the action potential transit, fluorescent nanodiamonds are functionalized to target specific areas of neurons. The functionalization is proven by different methodologies and the biocompatibility is investigated. Finally, the hybrid nanodiamond systems are shown to have increased incidence with the cell locations and the first reported ODMR TIRF experiments on such quantum nanosensors are presented.
LK http://hdl.handle.net/11093/6822
UL http://hdl.handle.net/11093/6822
LA eng
NO Fundação para a Ciência e Tecnologia | Ref. POCI-01-0145-FEDER-032619
DS Investigo
RD 14-sep-2024