Active Pixel Detectors For Mass Spectrometry Imaging

Abstract

In the framework of this thesis, an in-vacuum, high-voltage electron and ion imaging camera was developed. The system is particularly suitable for the detection of macromolecular ions of either polarity. The new camera is successfully tested on benchmark systems as wells as biologically relevant macromolecular tissue samples. Already now, time-of-flight mass spectrometry imaging (TOF-MSI) systems can benefit from several unique system capabilities. These are the combination of high signal-to-noise ratios, the multiplexed detection of events by the highly parallel detection system, the high sensitivity, the dynamic range, the large mass range and the simultaneous detection of position- and time-information by a single detector system. The research presented in this thesis represents a contribution to the toolbox available to investigate the building blocks of nature: atoms, molecules and molecular complexes. The first part of this thesis investigates the spatial and molecular structure of biologically relevant, complex macromolecular systems. In particular, the relationship between molecular structure and location, and biological or chemical functionality is investigated by the technique MSI. In the second part of this thesis, a technique is highlighted which bears the potential to provide fundamental understanding of chemical reactions and reaction dynamics of atoms and small molecules. This technique is applied to molecular spectroscopy and is called velocity map imaging (VMI). Keywords Mass spectrometry imaging, active pixel detectors, microchannel plates, CMOS Main conclusions Imaging systems that push the limits of spatial resolution and molecular sensitivity improve the understanding of the spatial structure and the composition of biological systems. This new, compact detector assembly is well-suited for imaging studies in mass spectrometry imaging, atomic and molecular physics research and related areas of research. The implementation and the application of this state-of-the art, pixelated, solid state detector has proven highly successful.