Research Sabine Van Doorslaer

Abstract

In quantum sensing, capable of sensing small magnetic fields due to motion of electrons in e.g. neurons, quantum bits (qubits) are preferably operational at room temperature. In this respect, organic molecular qubits (MQBs) bring many advantages such as long coherence times, exact positioning of the qubit, tunability and scalability. Yet, the implementation of MQBs is obstructed by the lack of single-qubit readout and the so far unknown relationship between qubit performance and chemical structure. Recent progress in the synthesis of stable organic molecules with two unpaired electron spins in their ground electronic state, i.e. diradicals, leads to an uncharted market for MQBs. The main selling point resides in the possibility of controlling the spin-spin interactions via chemical synthesis, and the huge potential for single-qubit optical readout. I will investigate new organic diradicals spanning the whole range of spin-spin interactions to establish a direct relation between the spin-spin interaction and their performance as MQBs. By combining my expertise in diradical spectroscopy with the expertise of my supervisors in electron spin resonance and optically-detected magnetic resonance, I aim to develop initialization, readout and manipulation processes for these MQBs. An intensive collaboration with chemical synthesis groups and a theoretician warrants a novel route towards quantum sensing with MQBs.

Researcher(s)

• Promoter: Cambré Sofie
• Co-promoter: Van Doorslaer Sabine

Research team(s)

• Nanostructured and organic optical and electronic materials (NANOrOPT)

Project type(s)

• Research Project

Abstract

Quantum technologies are widely believed to fundamentally change society in the near future, and extraordinary effort is being expended towards this goal. However potentially insurmountable challenges may loom on the horizon, e.g., lack of scalability, lack of tailorability and lack of qubit positionability. In OPTRIBITS, we will exploit the fundamental advantages of paramagnetic molecules for application as spin-based qubits in quantum technologies. Molecules have been shown to possess long ensemble coherence times up to the millisecond regime, with figures of merit exceeding 10,000. Molecules are nanoscopic in size, allowing for integration into devices at high densities enabling miniturization of quantum devices. Molecules are highly tailorable in terms of spin values, spin level structures, and excited state properties, enabling their adaptation to specific quantum technological objectives. Interqubit interactions can be exquisitely controlled, due to the high degree of qubit positionability in few-qubit or ordered arrangements, leading to well-defined and potentially switchable interactions. The main issue preventing the widespread use of molecular qubits has been the lack of convenient single-entity readout. As a result, the vast majority of results on molecular qubits have been obtained by ensemble measurements featuring large numbers of identical qubit copies. This proposal aims to remove this drawback by developing optically addressable molecular qubits. Optical addressing has been amply demonstrated to allow single entity readout because of the single photon sensitivity of optical detectors. To this end, we will design, prepare and study robust molecular qubits, which have spin states that allow for inducing spin polarization by optical pumping and are highly luminescent to allow for optical readout. In a second step, we will work towards device integration by immobilizing the qubit architectures on surfaces or by creating hybrid structures with carbon nanomaterials.

Researcher(s)

• Promoter: Cambré Sofie
• Co-promoter: Van Doorslaer Sabine

Research team(s)

• Nanostructured and organic optical and electronic materials (NANOrOPT)

Project type(s)

• Research Project

Abstract

The European Green Deal aims at transforming the current European economy into one that is sustainable, climate neutral, and circular by 2050. Many current anthropogenic activities lead however, to the release of harmful contaminants, such as phenolic compounds, in the environment. There is a need for sensitive, easy-to-use sensors to monitor these contaminants. Peroxidases are very versatile enzymes that are able to oxidize or convert many molecules, including phenolic compounds. Biosensors based on horseradish peroxidase have shown to be promising for detection of phenolic compounds. This project focuses on the use of dye-decolorizing peroxidases to extend the potential target analyte molecules. The bottleneck in the development of protein-based biosensors concerns the immobilization of the proteins on suitable supports. Here, titania will be used as support because of their biocompatibility. The key conditions of protein immobilization will be varied and their influence on the enzyme structure and activity evaluated. EPR techniques in combination with electrochemistry will be used to characterize the involved peroxidases, titania, and hybrid materials. This will lead to in-depth molecular insight in the systems, allowing a more rational design of the hybrid materials for biosensing, biotechnology, and biocatalysis. Finally, novel electrochemical biosensors will be developed and evaluated.

Researcher(s)

• Promoter: Van Doorslaer Sabine
• Co-promoter: De Wael Karolien
• Fellow: Cleirbaut Robine

Research team(s)

• Theory and Spectroscopy of Molecules and Materials (TSM²)

Project type(s)

• Research Project

Abstract

Uni4Equity general goal is to strengthen universities readiness to identify, map and respond to on-line and off-line sexual harassment (SH) at workplace and other relevant settings (classrooms, digital space), with an explicit but not exclusive attention to minority social groups. More specifically, it is aimed: 1) To reinforce universities teams, networks, and units in charge of gender equality issues through structural reforms, improved work processes and the engagement of key stakeholders for the prevention of SH; 2) To promote mutual learning and exchange of good practicesto identify and tackle SH at the university among different target groups; 3) To increase the social awareness about the importance of rejecting all forms of SH and the need to contribute to its prevention and combat among university members; 4) To improve the skills and the capacity of professionals and the availability of tools and resources to address and follow up it; 5) To reduce the exposition to SH risk factors at different levels of relations (interpersonal, institutional and social) for different target groups at the universities, including minority social groups; 6) To minimize the impacts SH may cause on victims; 7) To contribute to the acknowledge of the universities as an asset to prevent and response this problem; and, 8) To address prevention and combat of SH at university as a priority issue for gender equality promotion. Enhancing these aims requires an ecological approach that integrate strategies at different levels of prevention (primary, secondary and tertiary ones). The main target group will be students, teachers and administrative staff at the university, including social minority groups. It is proposed a multi-agency cooperation between universities and other relevant social actors to promote these changes through a mixed-method participative methodology

Researcher(s)

• Promoter: Schaubroeck Katrien
• Co-promoter: Hens Kristien
• Co-promoter: Van de Velde Sarah
• Co-promoter: Van Doorslaer Sabine

Research team(s)

• Center for Ethics

Project type(s)

• Research Project

Abstract

The weak spin-orbit interaction inherent to organic semiconductors makes them ideal candidates for spintronics applications. While typical spin lifetimes easily surpass those of their inorganic counterparts by several orders of magnitude, the main limitation in organic spin transporters is the spin diffusion length, often not exceeding 50 nm. It has now been established that spins in organic materials can be transported either by mobile charges or via spin exchange between localized polarons. The latter mechanism opens up an interesting new avenue toward longer spin diffusion lengths by increasing the intrinsic spin density of the materials. In 2019, record spin diffusion lengths of 1 um have been reported for the first time in a highly-doped polymer. In this project, I propose to investigate spin transport in paramagnetic polymers, a recently-discovered class of ultra-low-bandgap semiconductors exhibiting a triplet ground state and hence a large intrinsic spin density. Spin transport experiments will be performed in state-of-the-art spintronic devices based on spin pumping injection. In addition, the combination of electron paramagnetic resonance methods and supporting quantum-chemical computations will provide detailed information on spin delocalization and spin-spin-interactions. By expanding my study to a series of these polymers, structure-property relations can be elucidated and used to establish the fundamentals of spin transport in these innovative materials.

Researcher(s)

• Promoter: Van Doorslaer Sabine
• Co-promoter: Cambré Sofie
• Fellow: Van Landeghem Melissa

Research team(s)

• Theory and Spectroscopy of Molecules and Materials (TSM²)
• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

Optical materials are ubiquitous in present society. From the building blocks of displays and LEDs, to fibre optic communication for ultrafast internet, (plasmonic) nanostructures for photocatalysis, bulk heterojunctions for photovoltaics, probes for imaging, sensing and revealing reaction mechanisms in chemistry and catalysis and various nanostructures for nanophotonics applications. The in-depth knowledge on the nature and dynamics of the surface and bulk properties of these materials, such as the fate of electrons and holes that arise after optical excitation requires dedicated spectroscopic techniques that can reveal both steady-state and time-resolved properties of such materials. Fluorescence spectroscopy is one of the most versatile and sensitive techniques that can provide such information. Modern detectors are able to detect single photons that are emitted at time scales ranging from several picoseconds to seconds, and with energies spanning the entire UV, visible and NIR optical range. The system applied for is a versatile steady-state and time-resolved fluorescence spectrometer, that is highly modular and when combined with the already available infrastructure, provides a unique configuration allowing a wide range of experiments that provide information on a.o. ultrafast processes at picosecond timescales, delayed fluorescence from for example triplet states and with a sensitivity over a very broad wavelength range (200 – 1700nm) and accessibility to both ensemble and single-molecule detection from solutions, powders, nanoparticles, films and devices. The infrastructure will be applied in very different research fields, from photocatalysis to excitonic properties of nanomaterials, and from chemical reaction kinetics to photovoltaic and LED applications, which is also confirmed by the very diverse research topics of the 5 involved research teams.

Researcher(s)

• Promoter: Cambré Sofie
• Co-promoter: Johannessen Christian
• Co-promoter: Meynen Vera
• Co-promoter: Van Doorslaer Sabine
• Co-promoter: Verbruggen Sammy

Research team(s)

• Nanostructured and organic optical and electronic materials (NANOrOPT)

Project type(s)

• Research Project

Abstract

Through femtosecond pulsed laser micromachining a wide variety of materials such as ceramics (e.g. glass), hard metals (e.g. Hastelloy), and polymers can be processed with microscale resolution, offering innovation and beyond state-of-the-art research opportunities. To name a few, the planned research infrastructure would allow to tune the catalytic properties of surfaces, to enhance flow distribution, heat transfer and mass transfer in chemical reactors, to increase detection limit of photoelectrochemical sensors, to facilitate flow chemistry, to tailor-make EPR and TEM measurement cells, and to allow machine learning for hybrid additive manufacturing. Currently, the University of Antwerp lacks the necessary research infrastructure capable of processing such materials and surfaces with microscale precision. Access to femtosecond pulsed laser micromachining would yield enormous impact on ongoing and planned research both for the thirteen involved professors and ten research groups as for industry, essential to conduct research at the highest international level.

Researcher(s)

• Promoter: Breugelmans Tom
• Co-promoter: Bogaerts Annemie
• Co-promoter: Cool Pegie
• Co-promoter: De Wael Karolien
• Co-promoter: Maes Bert
• Co-promoter: Meynen Vera
• Co-promoter: Perreault Patrice
• Co-promoter: Van Doorslaer Sabine
• Co-promoter: Vanlanduit Steve
• Co-promoter: Verbeeck Johan
• Co-promoter: Verbruggen Sammy
• Co-promoter: Verwulgen Stijn
• Co-promoter: Watts Regan

Research team(s)

• Applied Electrochemistry & Catalysis (ELCAT)

Project type(s)

• Research Project

Abstract

Titanium-dioxide-based materials (titania) are semiconductors with many versatile applications in chemical catalysis, electrochemical sensing, food industry, energy conversion and many more. A considerable part of these applications rely on the electron-hole formation in titania by the absorption of light in the UV range. However, this restricts many practical applications, since sunlight has a limited UV content. Coloured titania, such as grey and black titania, can be formed via thermal, chemical or sonochemical reduction pathways. Although these materials absorb light in the visible range, there is many conflicting data reported about their activity and involved mechanistic pathways. There is also no consensus on the optimal synthesis routes to enhance specific favorable material characteristics. The large heterogeneity in coloured titania materials and their syntheses used in literature hampers a clear correlation between synthesis, electronic structure and activity. In this concerted action, we aim at a controlled alteration of the reduction conditions of porous titania linked to a direct determination of a variety of properties, such as electron traps, surface-adsorbed and surface-reacted species, bulk defects, band gap, polymorphs and pore sizes, and to activity measurements. For the latter we will test their capacity for photocatalytic reduction of CO2 and their applicability as electrode material in the electrochemical sensing of phenolic compounds in water. With this approach we guarantee that the results of the different experiments can be directly compared and correlated. This will allow determining the key factors governing the relation between synthesis, electronic and geometric structure and activity of coloured titania. This knowledge will be translated in optimal synthesis conditions for the here proposed applications, of importance in sustainable chemistry and development. The project makes use of the unique complementary expertise in the synthesis, experimental and theoretical characterization and application of titanium-dioxide-based materials available at UAntwerp.

Researcher(s)

• Promoter: Van Doorslaer Sabine
• Co-promoter: De Wael Karolien
• Co-promoter: Lamoen Dirk
• Co-promoter: Meynen Vera
• Co-promoter: Verbruggen Sammy

Research team(s)

• Theory and Spectroscopy of Molecules and Materials (TSM²)
• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

Catalysis is a key technology to achieve more efficient and greener organic synthesis. Complementary expertise on the development of new (homogenous and heterogeneous) catalysts (redox, photo and electrocatalysis) will be brought together with organic synthesis know-how in one center. Through collaboration of 5 research teams spanning two different faculties of the University of Antwerp a unique basis for innovative research, tackling challenging transformations in organic chemistry, is created. Cleavage and functionalization of strong bonds (carbon-nitrogen, carbon-oxygen, carbon-hydrogen and carbon-carbon bonds) in (small) organic molecules will be the target of the research activities of the consortium. The substrates will include petrochemical, biorenewable or waste compounds (e.g. CO2). The consortium combines advanced spectroscopy (including UV-vis, (in-situ) IR, multi-frequency EPR and NMR, circularly polarized and conventional Raman), sorption and quantum-chemical and molecular modeling techniques which will allow for fundamental insight in the active site of the catalyst and the reaction mechanism, providing a tool for rational catalyst/reaction development. Through shaping of the novel catalysts (e.g. indirect 3D printing) and evaluation in flow, effects of mass transport and sorption are evaluated revealing their industrial potential.

Researcher(s)

• Promoter: Maes Bert
• Co-promoter: Breugelmans Tom
• Co-promoter: Cool Pegie
• Co-promoter: Herrebout Wouter
• Co-promoter: Meynen Vera
• Co-promoter: Van Doorslaer Sabine

Research team(s)

• Organic synthesis (ORSY)

Project type(s)

• Research Project

Abstract

The SEP allowance will be used to support the final year of an on-going PhD student. The first part of the PhD trajectory was performed in the framework of the European Joint Doctorate network PARACAT (H2020-MSCA-ITN-2018-PARACAT-813209). This project is focussed on the implementation of advanced spectroscopic methods (Electron Paramagnetic Resonance, EPR) for cutting edge research in the field of catalysis. The work of Andre GUIDETTI focusses on a combined EPR-DFT methodology to gain mechanistic insights in photocatalyzed and transition metal catalyzed synthesis of a variety of organic molecules. While the study so far focused on the development of a combined toolbox of fluorescence, EPR and DFT techniques to study organic and copper-based photocatalysts, the final part of the work will focus on the use of this toolbox to clarify the role of radical pathways in reactions in comparison to redox paths involving transition metals. The focus will lie on the thiosulfonylation of unactivated alkenes with visible-light induced photocatalysis.

Researcher(s)

• Promoter: Van Doorslaer Sabine
• Fellow: Guidetti Andrea

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

The SEP allowance will be used to support the final year of an on-going PhD student. The first part of the PhD trajectory was performed in the framework of the European Joint Doctorate network PARACAT (H2020-MSCA-ITN-2018-PARACAT-813209). This project is focussed on the implementation of advanced spectroscopic methods (Electron Paramagnetic Resonance, EPR) for cutting edge research in the field of catalysis. The work of Ilenia SERRA focusses on the mechanistic insight in peroxidase activity towards industrial applications, with a focus on chlorite dismutase which is able to decompose harmful chlorite into harmless chloride and dioxygen of industrial and biotechnological interest. While the study so far has focused on the spectroscopic analysis of the resting states proteins under study, the understanding of the non-innocent effect of buffers on the spectroscopic parameters and the development of a freeze-trapping protocol to arrest intermediate reactive states of the protein, the last part of the PhD will focus on the EPR analysis of these intermediate states in order to understand the full biocatalytic mechanism. The spectroscopic approach developed for the study of the proteins will be further used study the effect of incorporation of the proteins in an inorganic matrix for industrial applications.

Researcher(s)

• Promoter: Van Doorslaer Sabine
• Fellow: Serra Ilenia

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

This budget is meant as maintenance support for the EPR infrastructure of UAntwerp, that consists of both pulsed and continuous-wave EPR spectrometers at X- (9.5 GHz) and W-band (95 GHz) frequencies. All spectrometers have also optical access for in-situ illumination.

Researcher(s)

• Promoter: Van Doorslaer Sabine

Research team(s)

• Biophysics and Biomedical Physics
• Theory and Spectroscopy of Molecules and Materials (TSM²)

Project type(s)

• Research Project

Abstract

Electron paramagnetic resonance (EPR) offers a unique tool for the characterization of paramagnetic systems found in biological and synthetic materials. It is used in very diverse fields, such as biology, chemistry, physics, medicine and materials sciences. EPR is a global name for many different techniques, of which the pulsed EPR spectroscopies are the most versatile ones, able to reveal very detailed structural information. The University of Antwerp hosts a pulsed and high-field EPR facility that is unique in Belgium. However, the basic continuous-wave EPR instrumentation that underlies this facility needs urgent upgrade. Moreover in recent years, the technical realization of arbitrary waveform generators (AWGs) with clock rates higher than a gigahertz has initiated a new era in EPR spectroscopy. These AWGs allow for novel experiments with shaped pulses through which more detailed information about the systems under study can be obtained. Use of these shaped pulses avails enormously increased sensitivity and spectral width. This is particularly important for the study of nanostructured materials and the detection of transiently formed active sites during catalysis, device operation or biological in-cell reactions, topics of major interest for the consortium. The requested extension of the EPR facility is essential to assure that EPR at UAntwerp remains at the forefront in this rapidly changing field.

Researcher(s)

• Promoter: Van Doorslaer Sabine
• Co-promoter: Breugelmans Tom
• Co-promoter: Cambré Sofie
• Co-promoter: Dewilde Sylvia
• Co-promoter: Maes Bert
• Co-promoter: Meynen Vera
• Co-promoter: Van den bergh Wim
• Co-promoter: Verbruggen Sammy

Research team(s)

• Theory and Spectroscopy of Molecules and Materials (TSM²)
• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

PARACAT aims at educating a group of young researchers to implement methods for cutting edge research in the field of catalysis, comprehensively exploring for the first time the role of open-shell species, an innovative area at the intersections between chemistry, physics and biology. The programme puts strong emphasis on ethics and social reflections by combining the scientific expertise of (bio)chemists, (bio)physicists and industrial partners with the input of an ethicist to form a new generation of scientists capable to take up appropriate societal responsibilities as experts in their field. PARACAT is set up by a consortium formed by 5 academic beneficiaries flanked by 1 research institute, 3 industrial organizations and 2 academic institutions as partners, collaborating in the research and training activities to offer 10 early-stage-researchers the possibility of being awarded with double doctoral degrees in two different European countries. The overall PARACAT programme will address the role of paramagnetism in catalysis with a focus on a knowledge-based bottom-up approach, integrating homogeneous, heterogeneous and bio-catalysis with the objective of 1) designing new catalysts based on earth abundant and safe elements; 2) discovery of new and more sustainable reaction pathways for the activation of small molecules and selective oxidations by learning from nature; 3) enabling new routes for polymerization and de-polymerization reactions. The training programme overcomes barriers between traditional disciplines providing top level tuition on topics spanning from advanced spectroscopic methods, synthesis and property characterization, to quantum chemical modelling, and on a full set of complementary skills .The goal is therefore to build a chain of knowledge whereby fundamental understanding is translated into practical applications by the synergistic interaction between academic and industrial partners, in an ethical and social dimension.

Researcher(s)

• Promoter: Van Doorslaer Sabine
• Co-promoter: Loobuyck Patrick
• Co-promoter: Maes Bert

Research team(s)

• Theory and Spectroscopy of Molecules and Materials (TSM²)
• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

Molecular hydrogen (H2) is an indispensable reactant in modern chemistry, used in many industrial processes for both commodity and fine chemicals synthesis. Unfortunately, the most widely spread production method of hydrogen (reforming of methane) is unsustainable due to the generation of carbon dioxide and moreover on a longer term not guaranteed because of the depletion of fossil feedstocks. Fortunately, many alternative solutions for (large scale) sustainable hydrogen production are technically far advanced, such as electrolysis. However, due to the issues related to the safe handling and storage of hydrogen, its use immediately after production (in situ generation and consumption) is the ideal approach for reactions using hydrogen as a reductant in the chemical industry. This ideally requires production and consumption of hydrogen in the same reaction vessel based on donor molecules which do not produce organic by-products. Thermochemical in situ water splitting combined with subsequent reduction reactions consuming hydrogen is a very attractive approach due to the practically unlimited availability of water and its very benign profile as a solvent (low cost, no environmental impact, non-toxic, non-flammable). However current (catalytic) methods for thermochemical water splitting are performed in gas phase and require very high temperatures (above 600 °C) and therefore are both extremely energy-demanding and incompatible with most organic molecules (these are not stable at these temperatures). The major objective of this project is therefore to develop thermochemical water splitting combined with immediate consumption of the generated hydrogen in a subsequent reduction (hydrogenation/hydrogenolysis) reaction at lower temperatures (200-300 °C) in liquid high temperature and pressure water (HTPW). At these temperatures, the properties of water remarkably change, providing much better solubility of organic substrates – often an issue for application of water in organic synthesis. Development of new synthetic methods for sustainable reduction reactions (nitro group reduction, hydrodeamination, hydrodehydroxylation) of both petrochemical and renewable feedstocks in HTPW are scheduled in which hydrogen gas will be generated in situ and consumed in the same reaction vessel. Several thermochemical systems for hydrogen gas generation will be evaluated, making use of both homogeneous and heterogeneous catalysts to bring down the required temperatures. The combined hydrogen production/reduction process will be optimized by variation of numerous parameters (temperature, pressure, concentration, catalysts and their loading, catalytic additives for the H2 generation). Due to the multiple (not independent) parameters which need to be varied, a "Design of Experiments (DoE)" approach will be used rather than the "vary one parameter at a time". Furthermore, design and optimization of all above-mentioned synthesis routes require a detailed insight into the reaction mechanisms on a molecular level. Therefore the mechanism of both the non-metal catalyzed reduction reactions and metal catalyzed hydrogen gas production will be studied with various experimental (spectroscopic) and computational techniques. In addition, for reactions relying on heterogeneous catalysis, thorough characterization of the catalyst's structural features by various techniques (e.g. XRD, UV-DR, Raman spectroscopy) will be undertaken.

Researcher(s)

• Promoter: Maes Bert
• Co-promoter: Cool Pegie
• Co-promoter: Herrebout Wouter
• Co-promoter: Van Doorslaer Sabine

Research team(s)

• Organic synthesis (ORSY)

Project type(s)

• Research Project

Abstract

Organometal trihalide perovskite solar cells have in the few years since their first introduction (in 2009) demonstrated very high power conversion efficiencies, up to 21% with potential for further increase. It is announced to become a game changer in the field of thin film photovoltaics, but this will critically depend on avoiding defect formation in the perovskite layer as well as at the interfaces with adjacent layers. The defects act as trapping centers for negative and positive charge carriers and as such impede the carriers to contribute to the photocurrent. The defects may result from the material synthesis and device fabrication methods, but they can also appear due to degradation, thereby reducing the useful lifetime of the solar cells. The main goal of my project is the identification and characterization of the defects that set a limitation to the solar cell performance. To learn about the geometric and electronic structure of these defects I will apply multi-frequency electron paramagnetic resonance (EPR) techniques which are able to reveal the nature of the defects and of their surroundings. Knowledge of the electronic structure and creation processes of the defects will allow to design better perovskite materials for these solar cells and to optimize the device fabrication process.

Researcher(s)

• Promoter: Goovaerts Etienne
• Co-promoter: Van Doorslaer Sabine
• Fellow: Van Landeghem Melissa

Research team(s)

• Nanostructured and organic optical and electronic materials (NANOrOPT)

Project type(s)

• Research Project

Abstract

Nature is by far the most versatile chemist and modern research efforts have harnessed the power of Nature by using biomolecules such as proteins as building blocks or targets for various technological applications. In many cases the immobilization of a protein in a synthetic matrix is essential. In particular protein-porous material hybrids have received much attention but their preparation have been non-trivial, often limited by the size compatibility between the pore and the protein and the surface properties. The quest for a suitable protein-matrix combination not only requires extensive synthetic optimization, but also the development of appropriate methodologies that can be used to determine the effect of the matrix on the structure and stability of the protein. In this multidisciplinary action, the stabilities, structures and dynamics of heme proteins (globins) immobilized in mesoporous silica or titania will be studied by EPR. This class of hybrid materials are themselves also of great interest because of potential electrochemical biosensing and biocatalysis applications. Novel orthogonally spin-labeled globins will be prepared and incorporated into (modified) mesoporous silica and titania. Pulse dipolar spectroscopy will be used to measure nanometric distance constraints within the free and immobilized globins. Combined with computational models, these measurements will provide unique insights into effects of incorporation on the tertiary structures and conformational flexibilities of the proteins. This action will not only result in the development of a generic analytical toolbox, based on spin-label EPR, for the characterization of proteins immobilized in matrices, but also lead to advances in the understanding and preparation of protein-porous material hybrids.

Researcher(s)

• Promoter: Van Doorslaer Sabine
• Fellow: Ching Hong Yue Vincent

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

Globins are globular heme-binding proteins that are widely distributed throughout life. Globin diversity is exceptional in nematodes and in the C. elegans genome 33 globin genes were discovered. Globin-3 attracted our attention as it is one of the few globins that gives a clear phenotype upon knockout: sterility. This globin is expressed in 20 to 30 neurons and in a specific region in the somatic gonad. It is expressed as two isoforms, predicted to be membrane-bound: one in the plasma membrane and one in the mitochondria. In this project, we will functionally characterize these two GLB-3 isoforms. After exact localization inside the worm, we will study how gonadal GLB-3 influences fertility and whether the neuronal GLB-3 affects worm behavior, with focus on oxygen and temperature sensing. To understand its full function in neurons and the gonad, we will also study electron transfer and ligand binding capacity of this globin. This will tell us whether it works via oxygen binding or by redox reactions inside the cell. Also putative enzymatic functions of GLB-3 will be tested. As it is very likely that this protein does not act solitary, we will search for its interaction partners, with special focus on superoxide dismutases. With this research strategy, we aim to understand the detailed biochemistry and function of GLB-3 in C. elegans. We also hope to further establish C. elegans as a perfect model for uncovering the wide functional diversity of globins.

Researcher(s)

• Promoter: Dewilde Sylvia
• Promoter: Van Doorslaer Sabine
• Co-promoter: Van Doorslaer Sabine

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

In 2016, around 12 million tonnes of phenol was produced for various processes such as the production of plastics, antibiotics and dyes. Through industrial and municipal waste, the phenolic compounds leach into the water reservoirs and can pose a threat to human health. There are several EU laws which regulate these contaminants however, these laws are sometimes outdated, vague and implementation in practice falls short. Therefore to gain more insight in the current situation of phenolic contaminants screening methods are crucial. Current enzymatic sensors studied in literature show an improved sensitivity compared to traditional methods due to the accumulation of detectable species, but have poor stability and need additional reagents. Therefore I want to develop a sensor which overcomes the drawbacks of enzymatic sensors but retains its improved sensitivity. My aim is to develop a sensitive, rapid and low cost electrochemical sensor with an ease of interpretation of results by non-specialists (through the use of an app on a smartphone with integrated LED). In the proposed detection strategy, a modified sensor will generate a change in current in the presence of phenolic contaminants upon illumination by a LED.

Researcher(s)

• Promoter: De Wael Karolien
• Co-promoter: Van Doorslaer Sabine
• Fellow: Neven Liselotte

Research team(s)

• Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)

Project type(s)

• Research Project

Abstract

Several important applications such as separation and sensors are directly influenced by the materials properties involved. The surface properties and their specific interactions with molecules are key components that needs to be controlled and understood in detail to further progress materials development and performance. Organophosphonic acid modification is a known modification method for metal oxides, adding versatility of interactions of organic molecules to the robust and structural advantages of the inorganic support. Although several studies exist on correlating synthesis conditions with surface properties, detailed knowledge on their impact on specific interactions with molecules at the molecular scale are still lacking. Therefore, we would like to combine knowledge on controlled synthesis and material characterization with studies of dynamic local interaction behavior via in-situ EPR with spin probes and in-situ IR. We aim at: elucidating the correlation of synthesis conditions and the resulting surface properties to local interaction behavior influenced by contributions of the (packing density and type of) functional groups, un-bonded reactive groups of the organophosphonic acid and the titania surface, together determining the observed overall adsorption behavior. Moreover, we aim at revealing important aspects of the surface modification mechanisms by studying the probe mobility during grafting, in and with the surface grafted layer.

Researcher(s)

• Promoter: Meynen Vera
• Co-promoter: Van Doorslaer Sabine
• Fellow: Sarker Rajib Kumar

Research team(s)

• Laboratory of adsorption and catalysis (LADCA)

Project type(s)

• Research Project

Abstract

Nature is by far the most versatile chemist and modern research efforts have harnessed the power of Nature by using biomolecules such as proteins as building blocks or targets for various technological applications. In many cases the immobilization of a protein in a synthetic matrix is essential. In particular protein-porous material hybrids have received much attention but their preparation have been non-trivial, often limited by the size compatibility between the pore and the protein and the surface properties. The quest for a suitable protein-matrix combination not only requires extensive synthetic optimization, but also the development of appropriate methodologies that can be used to determine the effect of the matrix on the structure and stability of the protein. In this multidisciplinary action, the stabilities, structures and dynamics of heme proteins (globins) immobilized in mesoporous silica or titania will be studied by EPR. This class of hybrid materials are themselves also of great interest because of potential electrochemical biosensing and biocatalysis applications. Novel orthogonally spin-labeled globins will be prepared and incorporated into (modified) mesoporous silica and titania. Pulse dipolar spectroscopy will be used to measure nanometric distance constraints within the free and immobilized globins. Combined with computational models, these measurements will provide unique insights into effects of incorporation on the tertiary structures and conformational flexibilities of the proteins. This study will not only result in the development of a generic analytical toolbox, based on spin-label EPR, for the characterization of proteins immobilized in matrices, but also lead to advances in the understanding and preparation of protein-porous material hybrids.

Researcher(s)

• Promoter: Van Doorslaer Sabine
• Fellow: Ching Hong Yue Vincent

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

In recent years, there has been a growing search for clean, environmental friendly methodologies for organic synthesis. Organic electrochemistry offers an interesting alternative to tackle the issues for organic transformations. Electrochemical synthesis mostly needs fewer steps and produces less waste with the electron as a cheap, clean and energetically efficient reagent. However, the applicability of electrosynthesis depends on the selection of the electrocatalyst as a way to decrease the energy demand of the reactions. In the current state of the art, these catalysts are still subject to further improvements. In our opinion, developing sufficient theoretical knowledge about the reaction mechanism on the electrode surface for very specific electrochemical reactions is essential to tune these catalysts. Therefore, we will use a combination of in situ electrochemistry and electron paramagnetic resonance (EPR) to unravel the underlying mechanism. The final goal is to develop an approach that provides an in-depth understanding of reaction mechanisms and that links the electrocatalytic and electrosynthetic features to the morphology and stability of the electrode material. To reach this goal, a combination of electrochemical techniques, in-line analytical methods and different EPR techniques will be used. New flow cells will be constructed in addition to existing static cells to unravel the electrode kinetics and to assess the activity of different electrocatalyst materials.

Researcher(s)

• Promoter: Breugelmans Tom
• Co-promoter: Van Doorslaer Sabine

Research team(s)

• Applied Electrochemistry & Catalysis (ELCAT)

Project type(s)

• Research Project

Abstract

The constantly increasing global energy demand and massive use of fossil fuels is putting a very heavy burden on our environment. Not surprisingly, policy makers world-wide are pressing for renewable and eco-friendly alternative energy sources. Solar energy is inexhaustible and offers many possibilities. In principle, organic solar cells (OSCs) would be ideal, since they are light, flexible, and offer the potential of large-area fabrication. Their cost can be kept low, provided nonfullerene OSCs with sufficient power conversion efficiencies can be found. The recent successes in synthesis of materials for non-fullerene OSCs are very promising. However, one of the biggest problems common to all OSCs is the poor stability of the cells. Advancements in OSC stability can only be obtained through in-depth knowledge of the molecular reaction paths and morphological changes that impair this stability. This in turn requires good assays to monitor and evaluate these processes. This project targets at the development of a systematic methodology, based on different electron paramagnetic resonance techniques, to study mechanistic steps in OSC degradation on a molecular level. The assays will be optimized for studies of both the organic core materials (blends) and the corresponding OSC devices. The methodology will be applied here to the case of non-fullerene OSCs, but will be generic for studies of other OSCs and related novel photovoltaic devices.

Researcher(s)

• Promoter: Van Doorslaer Sabine
• Co-promoter: Goovaerts Etienne
• Fellow: Sudakov Ivan

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

Organometal trihalide perovskite solar cells have in the few years since their first introduction (in 2009) demonstrated very high power conversion efficiencies, up to 21% with potential for further increase. It is announced to become a game changer in the field of thin film photovoltaics, but this will critically depend on avoiding defect formation in the perovskite layer as well as at the interfaces with adjacent layers. The defects act as trapping centers for negative and positive charge carriers and as such impede the carriers to contribute to the photocurrent. The defects may result from the material synthesis and device fabrication methods, but they can also appear due to degradation, thereby reducing the useful lifetime of the solar cells. The main goal of my project is the identification and characterization of the defects that set a limitation to the solar cell performance. To learn about the geometric and electronic structure of these defects I will apply multi-frequency electron paramagnetic resonance (EPR) techniques which are able to reveal the nature of the defects and of their surroundings. Knowledge of the electronic structure and creation processes of the defects will allow to design better perovskite materials for these solar cells and to optimize the device fabrication process.

Researcher(s)

• Promoter: Goovaerts Etienne
• Co-promoter: Van Doorslaer Sabine
• Fellow: Van Landeghem Melissa

Research team(s)

• Nanostructured and organic optical and electronic materials (NANOrOPT)

Project type(s)

• Research Project

Abstract

The heme-b containing enzymes chlorite dismutase and dye-decolourizing peroxidase belong to the same protein superfamily. Despite their high sequence homology and structural analogy, their enzymatic activity is very different. Chlorite dismutase is capable of degrading the strong and toxic oxidant chlorite to chloride and dioxygen. In contrast, dye-decolourizing peroxidases are able to degrade a large variety of molecules, including textile dyes and lignin. This project aims at understanding which local structural elements in the heme environment govern the observed high variation in enzymatic function. For this, advanced electron paramagnetic resonance spectroscopy in combination with protein engineering will be used as major tools to determine the local geometric and electronic structure of the heme site during the different steps in protein turnover. The same biophysical spectroscopic method will also be used to investigate the interaction of the enzymes with different heme-ligating molecules, such as inhibitors. Insight in the mechanistic working of the enzymes is essential in view of their potential technological applications, such as in bioremediation of the environmental pollutant chlorite or degradation of lignin in the transformation of biomass to biofuel.

Researcher(s)

• Promoter: Van Doorslaer Sabine

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

Organometal trihalide perovskite solar cells have in the few years since their first introduction (in 2009) demonstrated very high power conversion efficiencies, up to 18% with potential for further increase. It is announced to become a game changer in the field of thin film photovoltaics, but this will critically depend on avoiding defect formation in the perovskite layer as well as at the interfaces with adjacent layers. The defects act as trapping centers for negative and positive charge carriers and as such impede the carriers to contribute to the photocurrent. The defects may result from the material synthesis and device fabrication methods, but they can also increasingly appear due to degradation, thus reducing the useful lifetime of the solar cells. The main goal of my project is the identification of the defects that either set an initial limitation to the solar cell performance or else cause degradation of the solar cell during operation. To learn about the geometric and electronic structure of these defects I will apply multi-frequency electron paramagnetic resonance (EPR) techniques which are able to reveal the nature of the defects. Knowledge of the electronic structure and creation processes of the defects will allow designing better perovskite materials for these solar cells and to optimize the device fabrication.

Researcher(s)

• Promoter: Goovaerts Etienne
• Co-promoter: Van Doorslaer Sabine
• Fellow: Van Landeghem Melissa

Research team(s)

• Nanostructured and organic optical and electronic materials (NANOrOPT)

Project type(s)

• Research Project

Abstract

The goal of this project is the development of a generic platform for electron paramagnetic resonance spectroscopy (EPR) to unravel the electrocatalytic reaction mechanism. The constructed platform will be used to investigate parameters such as reaction kinetics, mechanism, mass transport, etc. For the elaboration of this platform we will focus on the reduction of benzyl bromide.

Researcher(s)

• Promoter: Breugelmans Tom
• Co-promoter: Van Doorslaer Sabine

Research team(s)

• Applied Electrochemistry & Catalysis (ELCAT)

Project type(s)

• Research Project

Abstract

This project represents a research contract awarded by the University of Antwerp. The supervisor provides the Antwerp University research mentioned in the title of the project under the conditions stipulated by the university. The AGRECHEM consortium is an excellence centre of the University of Antwerp, focusing on green and sustainable chemistry. One of the biggest future challenges is the production of fine chemicals in a sustainable way. The quest for synthetic routes that are at the same time eco-friendly and economically feasible requires a concerted input of scientists with a variety of specializations. The progress in synthesis goes hand in hand with progress in materials characterization. Therefore, the consortium brings together two main research groups on synthetic chemistry and three research units specialized in material characterization techniques with emphasis on gaining mechanistic insight in chemical reactions. The consortium aims at consolidating and increasing the existing excellence in sustainable chemistry at the University of Antwerp.

Researcher(s)

• Promoter: Cool Pegie
• Co-promoter: Goovaerts Etienne
• Co-promoter: Janssens Koen
• Co-promoter: Maes Bert
• Co-promoter: Van Doorslaer Sabine

Research team(s)

• Laboratory of adsorption and catalysis (LADCA)

Project type(s)

• Research Project

Abstract

The general objective of this project is to improve organic solar cell performance on the basis of a more detailed fundamental understanding of the underlying properties and processes - such as electronic structure, charge transfer and transport, loss processes and bulk heterojunction blend morphology development - taking advantage of chemical engineering of non-fullerene electron acceptor materials (with all their possible advantages and hurdles to overcome).

Researcher(s)

• Promoter: Goovaerts Etienne
• Co-promoter: Van Doorslaer Sabine

Research team(s)

• Nanostructured and organic optical and electronic materials (NANOrOPT)

Project type(s)

• Research Project

Abstract

The project aims at the development of biosensors for small molecules by incorporating globin proteins in nanoporous inorganic or hybrid organic-inorganic materials. This involves globin purification, synthesis and modification of the porous materials, and realization of the electrochemical cell. The structural and electronic properties of the globins will be monitored during the process with resonance Raman and electron paramagnetic resonance spectroscopy.

Researcher(s)

• Promoter: Van Doorslaer Sabine
• Co-promoter: Cool Pegie
• Co-promoter: De Wael Karolien
• Co-promoter: Dewilde Sylvia
• Co-promoter: Meynen Vera

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

In this project, we aim at the targeted immobilization of heme proteins (globins) in different organic/inorganic matrices opening the way to new approaches in electrochemistry. The ideal heme proteins in this context are globins, in which the function of the heme group is controlled by the surrounding protein matrix. Moreover, several globins show redox cycling properties.

Researcher(s)

• Promoter: Van Doorslaer Sabine
• Co-promoter: De Wael Karolien
• Co-promoter: Dewilde Sylvia
• Co-promoter: Meynen Vera

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

2 different globin enzymes will be incorporated in mesporous silicamaterials in this project. These 2 globins are neuroglobin and globin 26 of the nematode C. elegans and have en known redoxfunction. The incorporation of these globins wil be studies with spectroscopical techniques such as electron paramagnetic resonance (EPR) and resonance Raman spectroscopy (RRS). Further we will work out an EPR-based methodology in order to study the effect of incorporation of enzymes in matrices.

Researcher(s)

• Promoter: Van Doorslaer Sabine
• Co-promoter: Dewilde Sylvia
• Fellow: De Schutter Amy

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

Through spectacular developments in the passed 25 years, nuclear magnetic resonance (NMR) has become the most important spectrocopic technique in material sciences. First applied to the study of small molecules, it is currently used for many scientific questions in interdisciplinary fields. This is also the case for electron paramagnetic resonance (EPR), related to NMR, but that uses unpaired electrons to retrieve the spectroscopic information. These magnetic resonance (MR) techniques offer very broad application possibilities, both in liquid and solid state, in homogeneous and heterogeneous samples, in living organisms as well as in organic or mineral environment.It is also unsurpassed as non-invasive imaging techniques and becomes increasingly more important in biomedical research. Flanders and Belgium have a very valuable MR research community, active in many application areas and internationally recognized. Nevertheless, an overall and formalized structure was missing at a Flemish level, focused on grouping and exploiting the different research potential by facilitating the collaboration between complementary research groups and facilities. This was obtained by the FWO Wetenschappelijke Onderzoeksgemeenschap (FWO scientific research community,WOG) in this field (period 2002-2006), that brought together the different Flemish actors in magnetic resonance.In this follow-up project, MULTIMAR, international collaboration is at the center of attention by extension of the non-Flemish group from 4 to 10, on a total of 19 research groups, all active in virtually all application areas of spectroscopy and magnetic resonance imaging techniques.

Researcher(s)

• Promoter: Van Doorslaer Sabine

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand EU. UA provides EU research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Van Doorslaer Sabine

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

- Synthesis of nanoporous titania (and titania-silica) materials and detailed characterization (with spectroscopic techniques such as FTIR, Raman, porosity analysis, thermal analysis) - Testing of the nanomaterials in fotocatalytic applications - Elucidation of the synthesis mechanism of nanoporous materials via advanced EPR techniques

Researcher(s)

• Promoter: Cool Pegie
• Co-promoter: Van Doorslaer Sabine
• Fellow: Vinck Evi

Research team(s)

• Laboratory of adsorption and catalysis (LADCA)

Project type(s)

• Research Project

Abstract

Run and point set of AFM measurements for characterization of biofunctional coatings developed at VITO. Scientific support with relevant characterization techniques (Raman, IR, XPS, ...).

Researcher(s)

• Promoter: Van Doorslaer Sabine

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

This is a fundamental research project financed by the Research Foundation - Flanders (FWO). The project was subsidized after selection by the FWO-expert panel.

Researcher(s)

• Promoter: Moens Luc
• Co-promoter: Dewilde Sylvia
• Co-promoter: Van Doorslaer Sabine

Research team(s)

Project type(s)

• Research Project

Abstract

This project represents a research contract awarded by the University of Antwerp. The supervisor provides the Antwerp University research mentioned in the title of the project under the conditions stipulated by the university.

Researcher(s)

• Promoter: Goovaerts Etienne
• Co-promoter: Van Doorslaer Sabine

Research team(s)

• Nanostructured and organic optical and electronic materials (NANOrOPT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Doorslaer Sabine
• Fellow: Vinck Evi

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

Conjugated organic and organometallic compounds and their stable radicals, useful as organic semiconductors, will be synthesized and characterized using advanced pulse and multi-frequency EPR techniques. The combination with all-electron DFT quantum chemical calculations is essential to extract all available structural information contained in the spectroscopic data.

Researcher(s)

• Promoter: Van Alsenoy Kris
• Co-promoter: Blockhuys Frank
• Co-promoter: Goovaerts Etienne
• Co-promoter: Van Doorslaer Sabine

Research team(s)

Project type(s)

• Research Project

Abstract

In the first subproject, advanced EPR methods will be used to test the validity of the use of small peptide complexes to mimic the characteristics of Cu(II)-binding proteins. In the second subproject the same techniques will be used to determine the heme-pocket structure of a recently discovered globin of C. elegans.

Researcher(s)

• Promoter: Van Doorslaer Sabine
• Fellow: Nagy Nóra

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

The WOG groups different Flemish magnetic resonance specialists from different disciplines (physics, chemistry, biomedical sciences, ...). Magnetic resonance covers a broad research area differing both in the applied techniques (NMR, MRI, EPR) as in the type of applications. This diversity is also found within the WOG and together with associated (Wallon and international) research groups, the WOG initiates strong collaboration whereby the accessibility to the different NMR, MRI and EPR facilities within the network is enhanced and the complementarity of the facilities can be exploited at maximum. Furthermore,, the WOG will offer young scientists in the field a forum to present their research by organizing yearly symposia. In this respect, active participation of the members of the WOG to European activities will be supported.

Researcher(s)

• Promoter: Van Doorslaer Sabine

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

In some of the globin-like proteins a second domain is present next to the globin domain. In this project we focus on the biophysical characterization of two such classes of di-domain heme proteins : (a) globin-coupled sensors and (b) flavohemoglobnis. Insighti n to the structural, dynamical and electronic properties of these biomolecules. In the research project we aim to achieve this using different characterization techniques: absorption and resonance Raman spectroscopy, flash photolysis and CW and pulsed electron paramagnetic resonance.

Researcher(s)

• Promoter: Van Doorslaer Sabine
• Fellow: Desmet Filip

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

The goal of this project is the unravelling of subtle electronic and steric effects that controle the function of chiral homogeneous catalysts using advanced pulsed electron paramagnetic resonance (EPR) and electron nuclear double resonance (ENDOR) techniques. For this, the project focuses on the analysis of paramagnetic transition-metal-containing salen-type catalysts.

Researcher(s)

• Promoter: Van Doorslaer Sabine

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

This is a fundamental research project financed by the Research Foundation - Flanders (FWO). The project was subsidized after selection by the FWO-expert panel.

Researcher(s)

• Promoter: Goovaerts Etienne
• Co-promoter: Van Doorslaer Sabine

Research team(s)

• Nanostructured and organic optical and electronic materials (NANOrOPT)

Project type(s)

• Research Project

Abstract

This project focusses on the structure and structure-function determination of (i) cardial hERG PAS domain, (ii) the KChip subunits that influence ion channels and (iii) globin-coupled sensors that have been related to oxygen-sensing. The analyses will be done using advanced electron paramagnetic resonance techniques.

Researcher(s)

• Promoter: Van Doorslaer Sabine
• Co-promoter: Moens Luc
• Co-promoter: Snyders Dirk

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Doorslaer Sabine
• Fellow: Vinck Evi

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

In this project we will combine the unique possibilities of high-field and pulsed EPR techniques, ODMR and resonance Raman techniques present in the SffiAC and ECM laboratories (UA) with the synthetic and catalytic expertises of the Laboratory for Adsorption and Catalysis (UA) and DICOC (UG). This project will also occur in collaboration with Dr. D. Murphy (Dept. of Chemistry, Cardiff Univ.) who will complement the project with his expertise on CW ENDOR (see appendix I, bibliography and letter of support D. Murphy). In the first part, the formation of mesoporous materials will be studied. In a second part, the incorporation of metal complexes will be analyzed, studying the functionalization of the porous materials, the isolated metal complexes, the incorporation of the precursors and the final products. In a last step the catalytic activity of the systems will be tested. Structure-characterization methods will be used to determine the mechanisms of the catalytic activity. The aim of the project is to understand better the formation and location of the metal-ion sites in mesoporous systems and to link these to the analysis of the catalytic activity and reaction mechanisms to optimize selectively the synthesis of these catalysts.

Researcher(s)

• Promoter: Van Doorslaer Sabine
• Co-promoter: Cool Pegie

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

The N-terminal part of the cardiac K+-channel hERG contains a sequence (AA 1-90) belonging to the family of the PAS domains (characterized by 3D homology). Mutations identified in this domain have been shown to cause the LQT syndrome, in some cases by changing biophysical properties while in other cases by changing the trafficking and thus impeding the transport out of the ER to the plasmamembrane. The low expression of hERG-1b lacking this domain is consistent with the hypothesis that the PAS domain is important for trafficking. We and others have shown that mutations in' this domain are associated with the LOT syndrome. Some of these mutations display temperature dependence suggesting that these mutations change the folding of these domains. The KChlP subunjts were i.dentified as cytoplasmic 13-subunits 15. This group has expanded rapidly and we recently identified a new splice variant of KCh1P116. These subunits associate with the Kv4 subfamily increasing the expression at the level of the plasmamembrane bya factor 5-10. These results indicate that the association of KChlP with a o- subunit alters the trafficking of ion channels and thereby also determines in some extent the expression level. Furthermore, the subcellular localization (axon, dendrite, cell body) might be altered by the presence of KChIP. Recent results indicate that KChlP also associates with Kv1.5 indicating a more general role for these subunits.

Researcher(s)

• Promoter: Van Doorslaer Sabine
• Co-promoter: Raes Adam
• Co-promoter: Snyders Dirk

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Doorslaer Sabine

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

In this project the structure of proteins will be analysed using continuous-wave (CW) en pulsed electron paramagnetic resonance (EPR), resonance Raman scattering and absorption and fluorescence spectroscopy. The project can be divided into three parts. The first part comprises de study of globins. In the framework of this project, the structure of the heme pocket of neuroglobin and Spisula Solidissima nerve globin is presently being studied in our laboratory. In the second project, the copper binding of prions and prion related proteins, such as doppel, is investigated, with the aid of fluorescence spectroscopy and EPR. The third project comprises distance measurements on spinlabeled ionchannels, using EPR techniques. The purpose of these measurements is to reveal the influence of naturally occurring mutations on the structure (and thus the function) of the ionchannels. As our laboratory doesn't have any experience with the use of spinlabels, the first goal of this project is to perform test measurements on the pure spinlabel, in order to determine the optimum experimental conditions.

Researcher(s)

• Promoter: Van Doorslaer Sabine
• Fellow: Vinck Evi

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

Using continuous wave (CW) and pulse electron paramagnetic resonance (EPR) and the related electron nuclear double resonance (ENDOR) and electron double resonance (ELDOR) techniques different paramagnetic metalloproteins and paramagnetic centers in solids will be investigated. The study is mainly focused on the structural analysis of the iron-containing heme group in different globins and on the investigation of the nickel enzyme methyl-coenzyme M reductase and its model systems. In both cases the structural information can give direct access to the analysis of the different proposed biological functions of the proteins under study. In a broader framework, the above-mentioned techniques will be applied in the analysis of transition metal ions in photo-refractive materials and in catalytic systems. Furthermore, new EPR and ENDOR pulse sequencies will be developed aimed at improving spectral resolution and interpretation.

Researcher(s)

• Promoter: Van Doorslaer Sabine
• Co-promoter: Bouwen Gust
• Co-promoter: Goovaerts Etienne

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

Two spectroscopic techniques, electron paramagnetic resonance (EPR) and resonance Raman spectroscopy, will be used for the structure analysis of the iron-containing heme groups of different globins and of the possible copper(II) binding sites in prion proteins. In both cases, the obtained structural information can give direct access to the analysis of the different proposed biological functions of the proteins under study.

Researcher(s)

• Promoter: Van Doorslaer Sabine

Research team(s)

• Biophysics and Biomedical Physics

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Doorslaer Sabine

Research team(s)

Project type(s)

• Research Project