Development of three-dimensional diamond photonics platforms for neuronal research

This project aims for the development of three-dimensional (3D) intelligent scaffolds doped with nanodiamonds (ND) to construct photonic platforms for neuronal activity mapping, targeting pattern studies of signaling in brain organoids, and neurodegenerative disease models. The combination of nitrogen-vacancy centers (NV) in NDs and the state-of-the-art Optically Detected Magnetic Resonance (ODMR) technique can potentially enable a localized measure of single neurons’ action potentials and temperature shifts. The Two-Photon Polymerization (TPP) technique will be used for scaffolds fabrication and a custom-assembled confocal setup modified for simultaneous execution of ODMR experiments, which are capable of resolve the total height of 3D structures will be used for imaging. The NV centers in NDs are singular electronic structures that allows to study and manipulate the quantum state of the spin. An ODMR experimental setup allows for the detection of spin state shifts trough differences in the red fluorescence intensity emitted by nanodiamonds when excited by a 532 nm or 561 nm laser. The study of ODMR traces can also allow for the detection of magnetic fields and temperature changes. On the one hand, the 3D scaffolding has gained visibility in the scientific community due to its ability to better mimic cellular environments, not only in terms of spatial configuration but also in nutrients supply. On the other hand, it is very challenging to fabricate, culture, maintain and study these complex microenvironments. The TPP fabrication technique is a recently developed technique characterized by its nanometric capacity to create 3D structures when a focused laser strikes a photosensitive material. Doping the 3D polymeric structures’ surface with the biocompatible NDs would allow a nanoscale proximity of neurons adhering to the scaffolds, creating a sensitive platform for both electrical signaling and temperature shifts. The proximity is key for the measurement of these parameters, in accordance with the sensitivity of the ODMR technique. Parkinson’s Disease (PD) represents the second most prevalent neurodegenerative disorder in the world. Currently, there are more than one million people in Europe living with PD. To validate the technique in neurosciences, we aim to apply the sensing platforms to PD models, including the newest 3D spheroids and brain organoid models. The access to novel sensing parameters may unravel differences between healthy and PD models, opening possibilities for a deeper understanding of the disease, early diagnostics, or a platform for the development of personalized medicines. The research planned in this PhD aims to combine, for the first time, the advances in quantum metrology approaches with innovative 3D Parkinson's Disease model developments, which harbor the potential as early diagnostic tools or test-beds for personalized medicines.