Diamond based relaxometry for biosensing

FNDs show spin-dependent fluorescence allowing quantitative detection of electron spins and in certain cases even nuclear spins at ambient conditions by optical readout. FNDs emit stable fluorescence without photobleaching or photo blinking, far-red emission, long lifetime, and high quantum efficiency. Recently nanodiamonds with NV- centers (fluorescent nanodiamond particles, FNDs) opened a new window to detect free radical generation in intracellular environments and during chemical reactions at the nanoscale and at ambient conditions. This thesis focused on how free radicals cause pathological conditions and develop different diseases. In chapter 2 we evaluated nanoparticle uptake in micro and macro environments. In chapter 3 we estimated free radical generation in HUVECS cells under an arterial and venous range of shear stress with FNDs. In Chapter 4 we investigated free radical generation based on relaxation time in different organelles such as cytosol, mitochondria and the nucleus. The research conducted in this project with relaxometry based on fluorescence nanodiamond particles (FNDs) offers a powerful tool for detecting intracellular free radical generation under shear stress conditions and in the different organelles of a cell. Detection of free radical generation in different organelles and under different shear stress conditions may increase our understanding of the pathological conditions in the early stage of disease development.