Ferritin is a spherical metalloprotein, capable of storing and releasing iron in a controllable way. It is composed of a protein shell of about 12 nm and within its cavity, iron is stored in a... Show moreFerritin is a spherical metalloprotein, capable of storing and releasing iron in a controllable way. It is composed of a protein shell of about 12 nm and within its cavity, iron is stored in a mineral form. The ferritin core resembles an iron-based nanoparticle that is isolated from the environment by the ferritin shell, which makes ferritin an attractive element to be used in the fabrication of bioelectronic devices. Another intriguing aspect of ferritin is its potential relation to neurodegenerative diseases, such as Alzheimer’s and Parkinson’s. The relation is not yet well understood, but the studies indicate that dysfunctional ferritin appears to play an important role. This dissertation aims to characterize ferritin electrically and magnetically. First, the electrical properties of single ferritin are explored to understand the charge transport through ferritin, and additionally, the first ferritin single-electron transistor is obtained. Second, the magnetic properties of multiple ferritin particles are studied by electron paramagnetic resonance, which supplies information about the ferritin core. A model of the electron-spin structure of the ferritin core is proposed and extended to the ferritin signal from post-mortem brain tissues. Show less
Single-molecule spectroscopy has become a powerful method for using organic fluorescent molecules in numerous applications. Along with sensing applications in biology and solid-state physics or a... Show moreSingle-molecule spectroscopy has become a powerful method for using organic fluorescent molecules in numerous applications. Along with sensing applications in biology and solid-state physics or a variety of applications in quantum information technology, molecules offer interesting possibilities for fundamental research. One of the very interesting areas is the study of charge transport and electric field sensing at the nanoscale. Developing molecular nanosensors for electric fields can not only help to fundamentally explore the motion of charges in conductors and semiconductors but can also lead to very sensitive and accurate instruments for quasi-static charge tracing or even single-electron charge detection. Such research could eventually lead to the construction of precise electric field sensors that can act as an interface between the quantum state of an electron and the outside word. We developed fluorescence molecular systems and electronic circuits with the aim of electric-field sensing and optical detection of one single electron. Show less
