Neven L (2022) Singlet oxygen-based photoelectrochemical detection of phenolic contaminants. 234 p
Abstract: Phenolic compounds can be found everywhere in our daily lives but exhibit high toxicity, low (bio)degradability and hormone-disrupting effects when they are released in the environment. It is for this reason imperative to develop detection strategies for these pollutants. A promising approach involves the use of a photoelectrochemical (PEC) sensor. In this sensor, a photosensitiser (PS) type II, which generates 1O2 under illumination, is used to oxidise phenolic compounds present in the sample. The oxidised phenols are reduced at the electrode surface leading to the generation of an electrocatalytic redox cycle. In this thesis, an in-depth understanding, through the identification of the reactive oxygen species (ROS) in the PEC sensing mechanism, is obtained. The detection strategy is optimised by choosing the PS with the highest 1O2 production and by optimising the detection parameters so that the PEC sensor can be successfully applied for the detection of phenols in industrial samples. First, it was determined that the use of highly fluorinated zinc phthalocyanine derivatives, F52PcZn and F64PcZn, as photocatalysts was optimal for the sensing of phenol due to their high 1O2 production and improved single-site isolation. However, next to 1O2, it was shown that the ROS O2•- and H2O2 were also generated in the PEC sensor. Their contribution to the photocurrent response was studied by rotating disk electrode measurements in function of the pH and applied potential. After this, the PEC detection strategy was optimised in terms of pH and applied potential for the detection of doxycycline, cefadroxil, and phenol. It was found that the use of alkaline pH-levels led to nmol L-1-level detection limits. The combination with square wave voltammetry (SWV) was, also, proposed to allow the quantification and identification of phenolic compounds in a specific sample. At last, the developed PEC and SWV sensors were applied for the measurement of phenolic compounds in industrial water samples. The PEC sensor could follow the decrease of the phenolic concentration throughout the wastewater treatment process while the SWV sensor provided the electrochemical fingerprints of these samples. The thesis concluded that the use of the PEC sensor was advantageous in the measurement of lower concentrated phenolic samples due to its high sensitivity and fast measurement time in comparison to commercial test kits.
Keywords: Doctoral thesis; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)
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“Strain-Induced Exciton Hybridization in WS2 Monolayers Unveiled by Zeeman-Splitting Measurements”. Blundo E, Faria PE Jr, Surrente A, Pettinari G, Prosnikov MA, Olkowska-Pucko K, Zollner K, Wozniak T, Chaves A, Kazimierczuk T, Felici M, Babinski A, Molas MR, Christianen PCM, Fabian J, Polimeni A, Physical review letters 129, 067402 (2022). http://doi.org/10.1103/PHYSREVLETT.129.067402
Abstract: Mechanical deformations and ensuing strain are routinely exploited to tune the band gap energy and to enhance the functionalities of two-dimensional crystals. In this Letter, we show that strain leads also to a strong modification of the exciton magnetic moment in WS2 monolayers. Zeeman-splitting measurements under magnetic fields up to 28.5 T were performed on single, one-layer-thick WS2 microbubbles. The strain of the bubbles causes a hybridization of k-space direct and indirect excitons resulting in a sizable decrease in the modulus of they factor of the ground-state exciton. These findings indicate that strain may have major effects on the way the valley number of excitons can be used to process binary information in two-dimensional crystals.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
DOI: 10.1103/PHYSREVLETT.129.067402
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“Supercapacitive biofuel cells”. Pankratova G, Bollella P, Pankratov D, Gorton L, Current opinion in biotechnology 73, 179 (2022). http://doi.org/10.1016/J.COPBIO.2021.08.008
Abstract: Supercapacitive biofuel cells' (SBFCs) most recent advancements are herein disclosed. In conventional SBFCs the biocomponent is employed as the pseudocapacitive component, while in self-charging biodevices it also works as the biocatalyst. The performance of different types of SBFCs are summarized according to the categorization based on the biocatalyst employed: supercapacitive microbial fuel cells (sMFCs), supercapacitive biophotovoltaics (SBPV) and supercapacitive enzymatic fuel cells (s-EFCs). SBFCs could be considered as promising 'alternative' energy devices (low-cost, environmentally friendly, and technically undemanding electric power sources etc.) being suitable for powering a new generation of miniaturized electronic applications.
Keywords: A1 Journal article; Engineering sciences. Technology; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)
DOI: 10.1016/J.COPBIO.2021.08.008
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“Wearable hollow microneedle sensing patches for the transdermal electrochemical monitoring of glucose”. Parrilla M, Detamornrat U, Domínguez-Robles J, Donnelly RF, De Wael K, Talanta : the international journal of pure and applied analytical chemistry 249, 123695 (2022). http://doi.org/10.1016/J.TALANTA.2022.123695
Abstract: According to the World Health Organization, about 422 million people worldwide have diabetes, with 1.5 million deaths directly attributed each year. Therefore, there is still a need to effectively monitor glucose in diabetic patients for proper management. Recently, wearable patches based on microneedle (MN) sensors provide minimally invasive analysis of glucose through the interstitial fluid (ISF) while exhibiting excellent correlation with blood glucose. Despite many advances in wearable electrochemical sensors, long-term stability and continuous monitoring remain unsolved challenges. Herein, we present a highly stable electrochemical biosensor based on a redox mediator bilayer consisting of Prussian blue and iron-nickel hexacyanoferrate to increase the long-term stability of the readout coupled with a hollow MN array as a sampling unit for ISF uptake. First, the enzymatic biosensor is developed by using affordable screen-printed electrodes (SPE) and optimized for long-term stability fitting the physiological range of glucose in ISF (i.e., 2.5–22.5 mM). In parallel, the MN array is assessed for minimally invasive piercing of the skin. Subsequently, the biosensor is integrated with the MN array leaving a microfluidic spacer that works as the electrochemical cell. Interestingly, a microfluidic channel connects the cell with an external syringe to actively and rapidly withdraw ISF toward the cell. Finally, the robust MN sensing patch is characterized during in vitro and ex vivo tests. Overall, affordable wearable MN-based patches for the continuous monitoring of glucose in ISF are providing an advent in wearable devices for rapid and life-threatening decision-making processes.
Keywords: A1 Journal article; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)
DOI: 10.1016/J.TALANTA.2022.123695
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“Wearable wristband-based electrochemical sensor for the detection of phenylalanine in biofluids”. Parrilla M, Vanhooydonck A, Watts R, De Wael K, Biosensors and bioelectronics 197 (2022). http://doi.org/10.1016/J.BIOS.2021.113764
Abstract: Wearable electrochemical sensors are driven by the user-friendly capability of on-site detection of key biomarkers for health management. Despite the advances in biomolecule monitoring such as glucose, still, several unmet clinical challenges need to be addressed. For example, patients suffering from phenylketonuria (PKU) should be able to monitor their phenylalanine (PHE) level in a rapid, decentralized, and affordable manner to avoid high levels of PHE in the body which can lead to a profound and irreversible mental disability. Herein, we report a wearable wristband electrochemical sensor for the monitoring of PHE tackling the necessity of controlling PHE levels in PHE hydroxylase deficiency patients. The proposed electrochemical sensor is based on a screen-printed electrode (SPE) modified with a membrane consisting of Nafion, to avoid interferences in biofluids. The membrane also consists of sodium 1,2-naphthoquinone-4-sulphonate for the in situ derivatization of PHE into an electroactive product, allowing its electrochemical oxidation at the surface of the SPE in alkaline conditions. Importantly, the electrochemical sensor is integrated into a wristband configuration to enhance user interaction and engage the patient with PHE self-monitoring. Besides, a paper-based sampling strategy is designed to alkalinize the real sample without the need for sample pretreatment, and thus simplify the analytical process. Finally, the wearable device is tested for the determination of PHE in saliva and blood serum. The proposed wristband-based sensor is expected to impact the PKU self-monitoring, facilitating the daily lives of PKU patients toward optimal therapy and disease management.
Keywords: A1 Journal article; Engineering sciences. Technology; Product development; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)
DOI: 10.1016/J.BIOS.2021.113764
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“2-D rotational invariant multi sub band Schrödinger-Poisson solver to model nanowire transistors”. Sels D, Sorée B, Groeseneken G, 14th International Workshop on Computational Electronics, 85 (2010)
Keywords: A1 Journal article; Electron Microscopy for Materials Science (EMAT);
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“2D semiconductors at the Leuven pulsed field facility”. Bogaerts R, de Keyser A, van Bockstal L, van der Burgt M, van Esch A, Provoost R, Silverans R, Herlach F, Swinnen B, van de Stadt AFW, Koenraad PM, Wolter JH, Karavolas VC, Peeters FM, van de Graaf W, Borghs G, Physicalia magazine 19, 229 (1997)
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
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“The (3 + 2)D structure of oxygen deficient LaSrCuO3.52”. Hadermann J, Pérez O, Créon N, Michel C, Hervieu M, Journal of materials chemistry 17, 2344 (2007). http://doi.org/10.1039/b701449j
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 7
DOI: 10.1039/b701449j
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“3D FIB/SEM study of Ni4Ti3 precipitates in Ni-Ti alloys with different thermal-mechanical histories”. Cao S, Nishida M, Somsen C, Eggeler G, Schryvers D, , 02004 (2009). http://doi.org/10.1051/esomat/200902004
Abstract: The three-dimensional size, morphology and distribution of Ni4Ti3 precipitates growing in binary Ni-rich Ni-Ti alloys have been investigated via a slice view procedure in a Dual-Beam FIB/SEM system, in order to better stress-free Ni50.8Ti49.2 alloy with all four variants of precipitates and a compressed Ni51Ti49 alloy with aligned precipitates in one family were studied. The Ni4Ti3 precipitates reach a volume fraction of 9.6% in the reconstructed region of the stress-free alloy and 4.3% in the compressed one. In both cases, the mean volume, specific surface area, sphericity and aspect ratio of the precipitates are calculated and the Pair Distribution Functions of the precipitates are obtained. It is shown that most precipitates in the stress-free sample grow larger and have a more lenticular shape, while those in the compressed sample are more cylindrical. Deviations from these ideal shapes reveal internal steps in the stress-free sample and lamellae formation in the compressed one.
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
Times cited: 1
DOI: 10.1051/esomat/200902004
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“3D reconstruction of a Ni51Ti49 alloy with precipitates by FIB-SEM alice-and-view”. Cao S, Tirry W, Schryvers D, Materia Japan 46, 803 (2007)
Keywords: A3 Journal article; Electron microscopy for materials research (EMAT)
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“3D reconstruction of Ni4Ti3 precipitates in a Ni51Ti49 alloy in a FIB/SEM dual-beam system”. Cao S, Tirry W, van den Broek W, Schryvers D, Materials science forum 583, 277 (2008). http://doi.org/10.4028/www.scientific.net/MSF.583.277
Abstract: Ni4Ti3 precipitates play an important role in the shape memory and superelastic behaviour of thermo-mechanically treated Ni-Ti material. The 3D morphology and distribution of such precipitates with lenticular shape and rhombohedral atomic structure in the austenitic B2 matrix of a binary Ni-rich Ni-Ti alloy has been elucidated via a slice view procedure in a Dual-Beam FIB/SEM system. With the sequence of cross-section SE images obtained from the SEM, a 3D reconstruction has been achieved after proper alignment and image processing, from which both qualitative and quantitative analysis can be performed. Careful imaging is needed to ensure that all variants of the precipitates are observed with equal probability, regardless sample orientation. Moreover, due to the weak contrast of the precipitates, proper imaging conditions need to be selected to allow for semi-automated image treatment. Finally, a volume ratio of 10.2% for the Ni4Ti3 precipitates could be calculated, summed over all variants, which yields a net composition of Ni50.36Ti49.64 for the matrix, leading to an increase of 113 degrees for the martensitic start temperature Ms. Also, the expected relative orientation of the different variants of the precipitates could be confirmed. In the near future, other quantitative measures on the distribution of the precipitates can be expected.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Vision lab
DOI: 10.4028/www.scientific.net/MSF.583.277
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“3D strain fields surrounding Ni4Ti3: direct measurement and correlation with the R-phase”. Tirry W, Schryvers D, , 02032 (2009). http://doi.org/10.1051/esomat/200902032
Abstract: Strain fields introduced by coherent Ni4Ti3 precipitates in austenitic Ni-Ti are believed to be a possible origin of why the R-phase transformation is introduced as an extra step before transforming to the B19'. The presence of this strain field was already confirmed in the past by conventional transmission electron microscopy (TEM) techniques and measured quantitatively by high resolution TEM (HRTEM). This time the geometrical phase method is applied on HRTEM micrographs to measure the full 3D strain tensor of the strain fields. Since each atomic resolution micrograph only results in a 2D measurement of the strain, observations in two different zone orientations are combined to retrieve the 3 x 3 strain tensor. In this work observations in a [1-1 1](B2) and [1 0-1](B2) zone orientation are used and this in case of precipitates with a diameter of around 50nm. In a next step the measured strain tensor is compared to the calculated eigenstrain of the R-phase in reference to the B2 matrix. This comparison shows that the introduced strain is very similar to the eigenstrain of one R-phase variant. Since for both structures, Ni4Ti3 and R-phase, four orientation variants are possible, each variant of the R-phase is thus able to accommodate the strain field of one of the Ni4Ti3 variants.
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
DOI: 10.1051/esomat/200902032
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“65th birthdays of W. Owen Saxton, David J. Smith and Dirk Van Dyck / PICO 2013 From multislice to big bang”. Lichte H, Dunin-Borkowski R, Tillmann K, Van Aert S, Van Tendeloo G Amsterdam (2013).
Keywords: ME3 Book as editor; Electron microscopy for materials research (EMAT)
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“Ab initio approach to superexchange interactions in alkali doped fullerides AC60”. Nikolaev AV, Michel KH, AIP conference proceedings
T2 –, 18th International Winterschool/Euroconference on Electronic Properties, of Novel Materials, MAR 06-JUN 13, 2004, Kirchberg, AUSTRIA , 393 (2004). http://doi.org/10.1063/1.1812115
Abstract: The superexchange interactions between the fullerenes arise as a result of the electron transfer from the C-60 molecule to the alkali atom and back. We present a scheme, which is a configuration interaction approach based on the valence bond (Heitler-London) method. The effect of superexchange is described together with chemical bonding by constructing and solving a secular equation, rather than by using a perturbation treatment. We have considered 180degrees and 90degrees superexchange for the C-60 Cs-C-60 pathways. The calculations account for unusual electronic properties of polymer orthorhombic and quenched cubic phases of CsC60: two lines in nuclear magnetic resonance experiments, the development of a spin-singlet ground state and a decrease of magnetic susceptibility as T-->0.
Keywords: P1 Proceeding; Condensed Matter Theory (CMT)
DOI: 10.1063/1.1812115
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“Ab initio based atomic scattering amplitudes and {002} electron structure factors of InxGa1-xAs/GaAs quantum wells”. Titantah JT, Lamoen D, Schowalter M, Rosenauer A, Journal of physics : conference series 209, 012040 (2010). http://doi.org/10.1088/1742-6596/209/1/012040
Abstract: The atomic scattering amplitudes of the various atoms of the systems Ga1−xInxAs, GaAs1−xNx and InAs1−xNx are calculated using the density functional theory (DFT) approach. The scattering amplitudes of N, Ga, As and In in the model systems are compared with the frequently used Doyle and Turner values. Deviation from the latter values is found for small scattering vectors (s<0.3Å−1) and for these scattering vectors dependence on the orientation of the scattering vector and the chemical environment is reported. We suggest a parametrization of these modified scattering amplitudes (MASAs) for small scattering vectors (s<1.0Å−1). The MASAs are exploited within zero pressure classical Metropolis Monte Carlo (MC), finite temperature calculations to investigate the effect of quantum well size on the electron {002} structure factor (SF) of Ga1−xInxAs quantum wells.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
DOI: 10.1088/1742-6596/209/1/012040
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“Ab initio computation of the mean inner Coulomb potential of technological important semiconductors”. Schowalter M, Rosenauer A, Lamoen D, Kruse P, Gerthsen D, 1007, 233 (2005)
Keywords: A1 Journal article; Electron Microscopy for Materials Science (EMAT);
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“Accurate description of the van der Waals interaction of an electron-positron pair with the surface of a topological insulator”. Saniz R, Vercauteren S, Lamoen D, Partoens B, Barbiellini B, Journal of physics : conference series 505, 012002 (2014). http://doi.org/10.1088/1742-6596/505/1/012002
Abstract: Positrons can be trapped in localized states at the surface of a material, and thus quite selectively interact with core or valence surface electrons. Hence, advanced surface positron spectroscopy techniques can present the ideal tools to study a topological insulator, where surface states play a fundamental role. We analyze the problem of a positron at a TI surface, assuming that it is a weakly physisorbed positronium (Ps) atom. To determine if the surface of interest in a material can sustain such a physisorption, an accurate description of the underlying van der Waals (vdW) interaction is essential. We have developed a first-principles parameterfree method, based on the density functional theory, to extract key parameters determining the vdW interaction potential between a Ps atom and the surface of a given material. The method has been successfully applied to quartz and preliminary results on Bi2Te2Se indicate the existence of a positron surface state. We discuss the robustness of our predictions versus the most relevant approximations involved in our approach.
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Times cited: 2
DOI: 10.1088/1742-6596/505/1/012002
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“Accurate measurements of atomic displacements in La0.9Sr0.1MnO3 thin films grown on a SrTiO3 substrate”. Geuens P, Lebedev OI, van Dyck D, Van Tendeloo G s.l., page 1133 (2000).
Keywords: H3 Book chapter; Electron microscopy for materials research (EMAT); Vision lab
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Lobato I (2014) Accurate modeling of high angle electron scattering. Antwerpen
Keywords: Doctoral thesis; Electron microscopy for materials research (EMAT)
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Amin-Ahmadi B (2015) Adanced TEM investigation of the elementary plsticity mechanisms in palladium thin films at the nano scale. Antwerpen
Keywords: Doctoral thesis; Electron microscopy for materials research (EMAT)
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“Advanced electron microscopy and its possibilities to solve complex structures: application to transition metal oxides”. Van Tendeloo G, Hadermann J, Abakumov AM, Antipov EV, Journal of materials chemistry 19, 2660 (2009). http://doi.org/10.1039/b817914j
Abstract: Design and optimization of materials properties can only be performed through a thorough knowledge of the structure of the compound. In this feature article we illustrate the possibilities of advanced electron microscopy in materials science and solid state chemistry. The different techniques are briefly discussed and several examples are given where the structures of complex oxides, often with a modulated structure, have been solved using electron microscopy.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 9
DOI: 10.1039/b817914j
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“Advanced electron microscopy characterisation of important precipitation and ordering phenomena in shape memory systems”. Schryvers D, Shape memory and superelasticity 1, 78 (2015). http://doi.org/10.1007/s40830-015-0006-3
Abstract: The present paper discusses some important aspects of precipitation and ordering in alloy systems that show a martensitic transformation and can or are used as shape memory or superelastic metallic systems. The precipitates are investigated by a variety of conventional and advanced electron microscopy techniques, including atomic resolution, 3D slice-and-view, energy loss spectroscopy etc. Depending on the system, such secondary phases can decrease the probability of a displacive transformation by changing the phase stability in the system, such as in the case of NiAl or NiTiPd, or can mechanically hinder the passage of the transformation interface, as in NiTiNb. On the other hand, properly controlling the nucleation and growth of some precipitates can strongly improve the properties of some types of materials, as is the case for the well-known Ni4Ti3 precipitates.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
DOI: 10.1007/s40830-015-0006-3
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Goris B (2014) Advanced electron tomography : 3 dimensional structural characterisation of nanomaterials down to the atomic scale. Antwerpen
Keywords: Doctoral thesis; Electron microscopy for materials research (EMAT)
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“Advanced TEM and SEM methods applied to 3D nano- and microstructural investigations of Ni4Ti3 precipitates in Ni-Ti (SMA)”. Schryvers D, Tirry W, Cao S, Diffusion and defect data : solid state data : part B : solid state phenomena 172/174, 229 (2011). http://doi.org/10.4028/www.scientific.net/SSP.172-174.229
Abstract: Two different kinds of experimental approaches yielding three-dimensional structural information on metastable semi-coherent precipitates are demonstrated. By combining high-resolution images from two independent viewing directions a full description of the strain field surrounding a nano-sized Ni4Ti3 precipitate in Ni-Ti can be obtained. The principal axes and strains correlate well with the transformation strain of the observed R-phase transformation close to the precipitate. Using a slice-and-view procedure in a FIB/SEM dual-beam instrument, a three-dimensional voxel dataset is produced from which morphological and distributional information on the same precipitates can be obtained yielding new insight into the particular transformation paths of these alloys, relevant for their functional behaviour.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
DOI: 10.4028/www.scientific.net/SSP.172-174.229
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“Advanced TEM investigations on Ni-Ti shape memory material: strain and concentration gradients surrounding Ni4Ti3 precipitates”. Schryvers D, Tirry W, Yang Z, , 329 (2005)
Abstract: Lattice deformations and concentration gradients surrounding Ni4Ti3 precipitates grown by appropriate annealing in a Ni51Ti49 B2 austenite matrix are determined by a combination of TEM techniques. Quantitative Fourier analysis of HRTEM images reveals a deformed nanoscale region with lattice deformations up to 2% while EELS and EDX indicate a Ni depleted zone up to 150 nm away from the matrix-precipitate interface.
Keywords: P1 Proceeding; Electron microscopy for materials research (EMAT)
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“Advanced TEM studies of martensite and related phase transformations”. Schryvers D s.l., page 947 (1999).
Keywords: H1 Book chapter; Electron microscopy for materials research (EMAT)
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“Aerosol synthesis and characterization of ultrafine fullerene particles”. van Cleempoel A, Joutsensaari J, Kauppinen E, Gijbels R, Claeys M, Fullerene science and technology 6, 599 (1998). http://doi.org/10.1080/10641229809350223
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Times cited: 3
DOI: 10.1080/10641229809350223
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“Aerosol synthesis of nanostructured, ultrafine fullerene particles”. Joutsensaari J, Ahonen PP, Tapper U, Kauppinen EI, Pauwels B, Amelinckx S, Van Tendeloo G, (1999)
Keywords: P3 Proceeding; Electron microscopy for materials research (EMAT)
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Li B (2012) Aharonov-Bohm effect in semiconductor quantum rings. Antwerpen
Keywords: Doctoral thesis; Condensed Matter Theory (CMT)
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“Alternative metals for advanced interconnects”. Adelmann C, Wen LG, Peter AP, Pourtois G, et al, 2014 Ieee International Interconnect Technology Conference / Advanced Metallization Conference (iitc/amc) , 173 (2014)
Abstract: We discuss the selection criteria for alternative metals in order to fulfill the requirements necessary for interconnects at half pitch values below 10 nm. The performance of scaled interconnects using transition metal germanides and CoAl alloys as metallization are studied and compared to conventional Cu and W interconnects.
Keywords: P1 Proceeding; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
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