“Conformation-Dependent Monolayer and Bilayer Structures of an Alkylated TTF Derivative Revealed using STM and Molecular Modeling”. Delfino CL, Hao Y, Martin C, Minoia A, Gopi E, Mali KS, Van der Auweraer M, Geerts YH, Van Aert S, Lazzaroni R, De Feyter S, The Journal of Physical Chemistry C 127, 23023 (2023). http://doi.org/10.1021/acs.jpcc.3c04913
Abstract: In this study, the multi-layer self-assembled molecular network formation of an alkylated tetrathiafulvalene compound is studied at the liquid-solid interface between 1-phenyloctane and graphite. A combined theoretical/experimental approach associating force-field and quantum-chemical calculations with scanning tunnelling microscopy is used to determine the two-dimensional self-assembly beyond the monolayer, but also to further the understanding of the molecular adsorption conformation and its impact on the molecular packing within the assemblies at the monolayer and bilayer level.
Keywords: A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ;
Impact Factor: 3.7
DOI: 10.1021/acs.jpcc.3c04913
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“Combined macro X-ray fluorescence (MA-XRF) and pulse phase thermography (PPT) imaging for the technical study of panel paintings”. Deleu N, Hillen M, Steenackers G, Borms G, Janssens K, Van der Stighelen K, Van der Snickt G, Talanta : the international journal of pure and applied analytical chemistry 270, 125533 (2024). http://doi.org/10.1016/J.TALANTA.2023.125533
Abstract: Museum staff usually relies on a proven combination of X-ray radiography (XRR) and infrared reflectography (IRR) to study paintings in a non-destructive manner. In the last decades, however, the research toolbox of heritage scientists has expanded considerably, with a prime example being macro X-ray fluorescence (MA-XRF), producing element-specific images. The goal of this article is to illustrate the added value of augmenting MA-XRF with pulse phase thermography (PPT), a variant of active infrared thermographic imaging (IRT), which is an innovative diagnostic method that is able to reveal variations between or in materials, based on a different response to minor fluctuations in temperature when irradiated with optical radiation. By examining three 16thand 17th-century panel paintings we assess the extent in which combined MA-XRF and PPT contributes to a better understanding of two commonly encountered interventions to panel paintings: (a) Anstuckungen (enlargement of the panel) or (b) substitutions (replacement of part of the panel). Yielding information from different depths of the painting, these two techniques proved highly complementary with IRR and XRR, expanding the understanding of the build-up, genesis, and material history of the paintings. While MA-XRF documented the interventions to the wooden substrate indirectly by revealing variations in painting materials, paint handling and/ or layer sequence between the original part and the extended or replaced planks, PPT proved beneficial for the study of the wooden support itself, by providing a clear image of the wood structure quasi-free of distortion by the superimposed paint or cradling. XRR, on the other hand, revealed other features from the wood structure, not visible with PPT, and allowed looking through the wooden panels, revealing e.g. the dowels used for joining the planks. Additionally, IRR visualised dissimilarities in the underdrawings. In this way, the results indicate that PPT has the potential to become an acknowledged add-on to the expanding set of imaging methods for paintings, especially when used in combination with MA-XRF, IRR and XRR.
Keywords: A1 Journal article; Art; Antwerp Cultural Heritage Sciences (ARCHES); Antwerp X-ray Imaging and Spectroscopy (AXIS)
Impact Factor: 6.1
DOI: 10.1016/J.TALANTA.2023.125533
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“The effect of sintering and Pd-doping on the conversion of CO to CO2 on SnO2 gas sensor materials”. Delabie L, Honoré, M, Lenaerts S, Huyberechts G, Roggen J, Maes G, Sensors And Actuators B-Chemical 44, 446 (1997). http://doi.org/10.1016/S0925-4005(97)00170-6
Abstract: The principal aim of this work is to study the effect of the processes of sintering and Pd doping of SnO2 gas sensor materials on the conversion of CO to CO2. For this purpose, the gas phase above screen printed sensor material is investigated using FTIR spectroscopy, while surface area, porosity and particle size measurements are performed on the SnO2 powders. During sintering, larger agglomerates of primary particles are formed, which results in a larger conversion degree of CO. The effect of Pd doping of the tin dioxide film on the CO conversion is more pronounced. The transformation of CO starts at a lower temperature and the conversion degree increases remarkably.
Keywords: A1 Journal article
Impact Factor: 5.401
DOI: 10.1016/S0925-4005(97)00170-6
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“Mechanisms for the trimethylaluminum reaction in aluminum oxide atomic layer deposition on sulfur passivated germanium”. Delabie A, Sioncke S, Rip J, van Elshocht S, Caymax M, Pourtois G, Pierloot K, The journal of physical chemistry: C : nanomaterials and interfaces 115, 17523 (2011). http://doi.org/10.1021/jp206070y
Abstract: Germanium combined with high-κ dielectrics is investigated for the next generations of CMOS devices. Therefore, we study reaction mechanisms for Al2O3 atomic layer deposition on sulfur passivated Ge using calculations based on density functional theory and total reflection X-ray fluorescence (TXRF). TXRF indicates 6 S/nm2 and 4 Al/nm2 after the first TMA/H2O reaction cycle, and growth inhibition from the second reaction cycle on. Calculations are performed on molecular clusters representing −GeSH surface sites. The calculations confirm that the TMA reaction does not affect the S content. On fully SH-terminated Ge, TMA favorably reacts with up to three −GeSH sites, resulting in a near tetrahedral Al coordination. Electron deficient structures with a GeS site shared between two Al atoms are proposed. The impact of the cluster size on the structures and reaction energetics is systematically investigated.
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4.536
Times cited: 9
DOI: 10.1021/jp206070y
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“Hybrid magnetic-plasmonic nanoparticle probes for multimodal bioimaging”. dela Encarnacion C, Lenzi E, Henriksen-Lacey M, Molina B, Jenkinson K, Herrero A, Colas L, Ramos-Cabrer P, Toro-Mendoza J, Orue I, Langer J, Bals S, Jimenez de Aberasturi D, Liz-Marzan LM, The journal of physical chemistry: C : nanomaterials and interfaces 126, 19519 (2022). http://doi.org/10.1021/ACS.JPCC.2C06299
Abstract: Multimodal contrast agents, which take advantage of different imaging modalities, have emerged as an interesting approach to overcome the technical limitations of individual techniques. We developed hybrid nanoparticles comprising an iron oxide core and an outer gold spiky layer, stabilized by a biocompatible polymeric shell. The combined magnetic and optical properties of the different components provide the required functionalities for magnetic resonance imaging (MRI), surface-enhanced Raman scattering (SERS), and fluorescence imaging. The fabrication of such hybrid nanoprobes comprised the adsorption of small gold nanoparticles onto premade iron oxide cores, followed by controlled growth of spiky gold shells. The gold layer thickness and branching degree (tip sharpness) can be controlled by modifying both the density of Au nanoparticle seeds on the iron oxide cores and the subsequent nanostar growth conditions. We additionally demonstrated the performance of these hybrid multifunctional nanoparticles as multimodal contrast agents for correlative imaging of in vitro cell models and ex vivo tissues.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 3.7
Times cited: 10
DOI: 10.1021/ACS.JPCC.2C06299
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“Ferrihydrite precipitation in groundwater-fed river systems (Nete and Demer river basins, Belgium) : insights from a combined Fe-Zn-Sr-Nd-Pb-isotope study”. Dekov VM, Vanlierde E, Billström K, Gatto Rotondo G, van Meel K, Darchuk L, Van Grieken R, et al, Chemical geology 386, 1 (2014). http://doi.org/10.1016/J.CHEMGEO.2014.07.023
Abstract: Two groundwater-fed river systems (Nete and Demer, Belgium) carry red suspended material that settles on the river bed forming red sediments. The local aquifer that feeds these river systems is a glauconite-rich sand, which provides most of the dissolved Fe to the rivers. The solid component of these systems, i.e., the red suspended material and sediments, has a simple mineralogy (predominantly ferrihydrite), but shows a complex geochemistry pointing out the different processes contributing to the river chemistry: (1) the red sediments have higher transition metal (excluding Cu) and detrital element (e.g., Si, Al, K, Rb, etc.) concentrations than the red suspended matter because of their longer residence time in the river and higher contribution of the background (aquifer) component, respectively; (2) the red suspended material and sediments have inherited their rare earth element (REE) patterns from the aquifer; (3) the origin of Sr present in the red suspended matter and red sediments is predominantly marine (i.e., Quaternary calcareous rocks), but a small amount is geogenic (i.e., from detrital rocks); (4) Pb in both solids originates mostly from anthropogenic and geogenic sources; (5) all of the anthropogenic Pb in the red suspended material and sediments is hosted by the ferrihydrite; (6) Nd budget of the red riverine samples is controlled by the geogenic source and shows little anthropogenic component; (7) the significant Fe- and Zn-isotope fractionations are in line with the previous studies. Their fractionation patterns do not correlate, suggesting that the processes controlling the isotope geochemistry of Fe and Zn are different: oxidation/reduction most likely governs the Fe-isotope fractionation, whereas adsorption/desorption or admixing of anthropogenic sources controls the isotope fractionation of Zn.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.CHEMGEO.2014.07.023
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“Determination of protein-bound copper and zinc in some organs of the cuttlefish Sepia officinalis L”. Decleir W, Vlaeminck A, Geladi P, Van Grieken R, Comparative biochemistry and physiology : B : biochemistry and molecular biology 60, 347 (1978). http://doi.org/10.1016/0305-0491(78)90057-3
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0305-0491(78)90057-3
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“Facile morphology-controlled synthesis of organolead iodide perovskite nanocrystals using binary capping agents”. Debroye E, Yuan H, Bladt E, Baekelant W, Van der Auweraer M, Hofkens J, Bals S, Roeffaers MBJ, ChemNanoMat : chemistry of nanomaterials for energy, biology and more 3, 223 (2017). http://doi.org/10.1002/CNMA.201700006
Abstract: Controlling the morphology of organolead halide perovskite crystals is crucial to a fundamental understanding of the materials and to tune their properties for device applications. Here, we report a facile solution-based method for morphology-controlled synthesis of rod-like and plate-like organolead halide perovskite nanocrystals using binary capping agents. The morphology control is likely due to an interplay between surface binding kinetics of the two capping agents at different crystal facets. By high-resolution scanning transmission electron microscopy, we show that the obtained nanocrystals are monocrystalline. Moreover, long photoluminescence decay times of the nanocrystals indicate long charge diffusion lengths and low trap/defect densities. Our results pave the way for large-scale solution synthesis of organolead halide perovskite nanocrystals with controlled morphology for future device applications.
Keywords: A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
Impact Factor: 2.937
Times cited: 19
DOI: 10.1002/CNMA.201700006
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“Evaluation of time-of-flight secondary ion mass spectrometry for metal contamination monitoring on wafer surfaces”. de Witte H, de Gendt S, Douglas M, Conard T, Kenis K, Mertens PW, Vandervorst W, Gijbels R, Journal of the electrochemical society 147, 13 (2000). http://doi.org/10.1149/1.1393457
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.259
Times cited: 14
DOI: 10.1149/1.1393457
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“The electrochemistry of a gelatin modified gold electrode”. De Wael K, Verstraete A, van Vlierberghe S, Dejonghe W, Dubruel P, Adriaens A, International journal of electrochemical science 6, 1810 (2011)
Abstract: This paper discusses the electrochemical behaviour of gelatin coated gold electrodes in physiological pH conditions in a potential window −1.5 till 1.0 V vs SCE by performing cyclic voltammetry. A comparison is made between gelatin A and gelatin B, which have respectively a positive and a negative net charge at physiological pH. The deposition of gelatin onto the gold surface is confirmed by means of attenuated total reflection-infrared (ATR-IR) spectroscopic analyses.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 1.469
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“The use of potentiometric sensors to study (bio)molecular interactions”. De Wael K, Daems D, Van Camp G, Nagels LJ, Analytical chemistry 84, 4921 (2012). http://doi.org/10.1021/AC3005428
Abstract: Potentiometric sensors were used to study molecular interactions in liquid environments, with sensorgram methodology. This is demonstrated with a lipophilic rubber-, and with a collagen based hydrogel sensor coating. The investigated molecules were promazine and tartaric acid respectively. The sensors were placed in a hydrodynamic wall jet system for the recording of sensorgrams. mV sensor responses were first converted to a signal, expressing the concentration of adsorbed organic ions. Using a linearization method, a pseudo first order kinetic model of adsorption was shown to fit the experimental results perfectly. Kass, kon and koff values were calculated.. The technique can be used over 4 decades of concentration, and it is very sensitive to low MW compounds as well as to multiply charged large biomolecules. This study is the first to demonstrate the application of potentiometric sensors as an alternative and complement to SPR methods.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 6.32
Times cited: 10
DOI: 10.1021/AC3005428
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“Electrochemical determination of hydrogen peroxide with cytochrome c peroxidase and horse heart cytochrome c entrapped in a gelatin hydrogel”. De Wael K, Bashir Q, van Vlierberghe S, Dubruel P, Heering HA, Adriaens A, Bioelectrochemistry: an international journal devoted to electrochemical aspects of biology and biological aspects of electrochemistry 83, 15 (2012). http://doi.org/10.1016/J.BIOELECHEM.2011.07.001
Abstract: A novel and versatile method, based on a membrane-free enzyme electrode in which both the enzyme and a mediator protein are entrapped in a gelatine hydrogel was developed for the fabrication of biosensors. As a proof of principle, we prepared a hydrogen peroxide biosensor by successfully entrapping both horse heart cytochrome c (HHC) and Saccharomyces cerevisae cytochrome c peroxidase (CCP) in a gelatin matrix which is immobilized on a gold electrode. This electrode was first pretreated with 6-mercaptohexanol. The biosensor displayed a rapid response and an expanded linear response range from 0 to 0.3 mM (R = 0.987) with a detection limit of 1 × 10− 5 M in a HEPES buffer solution (pH 7.0). This method of encapsulation is now further investigated for industrial biosensor applications.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 3.346
Times cited: 31
DOI: 10.1016/J.BIOELECHEM.2011.07.001
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“Reduced Na2+xTi4O9 composite : a durable anode for sodium-ion batteries”. De Sloovere D, Safari M, Elen K, D'Haen J, Drozhzhin OA, Abakumov AM, Simenas M, Banys J, Bekaert J, Partoens B, Van Bael MK, Hardy A, Chemistry of materials 30, 8521 (2018). http://doi.org/10.1021/ACS.CHEMMATER.8B03301
Abstract: Sodium-ion batteries (SIBs) are potential cost-effective solutions for stationary energy storage applications. Unavailability of suitable anode materials, however, is one of the important barriers to the maturity of SIBs. Here, we report a Na2+xTi4O9/C composite as a promising anode candidate for SIBs with high capacity and cycling stability. This anode is characterized by a capacity of 124 mAh g(-1) (plus 11 mAh g(-1) contributed by carbon black), an average discharge potential of 0.9 V vs Na/Na+, a good rate capability and a high stability (89% capacity retention after 250 cycles at a rate of 1 degrees C). The mechanisms of sodium insertion/deinsertion and of the formation of Na2+xTi4O9/C are investigated with the aid of various ex/in situ characterization techniques. The in situ formed carbon is necessary for the formation of the reduced sodium titanate. This synthesis method may enable the convenient synthesis of other composites of crystalline phases with amorphous carbon.
Keywords: A1 Journal article; Condensed Matter Theory (CMT)
Impact Factor: 9.466
Times cited: 7
DOI: 10.1021/ACS.CHEMMATER.8B03301
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“Pd-catalyzed decarboxylation of glutamic acid and pyroglutamic acid to bio-based 2-pyrrolidone”. De Schouwer F, Claes L, Claes N, Bals S, Degrève J, De Vos DE, Green chemistry : cutting-edge research for a greener sustainable future 17, 2263 (2015). http://doi.org/10.1039/c4gc02194k
Abstract: In order to recycle nitrogen from nitrogen-rich waste streams, particularly protein waste, we studied the decarboxylation of pyroglutamic acid and glutamic acid in a one-pot reaction to bio-based 2-pyrrolidone. After the screening of a wide range of supported Pd and Pt catalysts, 5 wt% Pd/Al2O3 displayed the highest yield (70%) and selectivity (81%) for the decarboxylation of pyroglutamic acid in water at 250 °C and under an inert atmosphere. Side products originate from consecutive reactions of 2-pyrrolidone; different reaction pathways are proposed to explain the presence of degradation products like propionic acid, γ-hydroxybutyric acid, γ-butyrolactone and methylamine. An extensive study of the reaction parameters was performed to check their influence on selectivity and conversion. This heterogeneous catalytic system was successfully extended to the conversion of glutamic acid.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 9.125
Times cited: 47
DOI: 10.1039/c4gc02194k
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“Configuration-interaction excitonic absorption in small Si/Ge and Ge/Si core/shell nanocrystals”. de Oliveira EL, Albuquerque EL, de Sousa JS, Farias GA, Peeters FM, The journal of physical chemistry: C : nanomaterials and interfaces 116, 4399 (2012). http://doi.org/10.1021/jp2088516
Abstract: The excitonic properties of Si(core)/Ge(shell) and Ge(core)/Si(shell) nanocrystals (NC's) with diameters of similar to 1.9 nm are investigated using a combination density functional ab initio method to obtain the single particle wave functions and a configuration interaction method to compute the exciton fine structure and absorption coefficient. These core/shell structures exhibit type II confinement, which is more pronounced for the Si/Ge NC as a consequence of strain. The absorption coefficients of these NC's exhibit a single dominant peak, which has a much larger oscillator strength than the multipeaks found for pure Si and Ge NC's. The exciton lifetime in Si, Ge, and Ge/Si shows a small i:emperature dependence in the range 10-300 K, whereas in Si/Ge, the exciton lifetime decreases more than an order of magnitude in the same temperature range.
Keywords: A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Impact Factor: 4.536
Times cited: 44
DOI: 10.1021/jp2088516
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“Importance of plasma discharge characteristics in plasma catalysis: Dry reforming of methane vs. ammonia synthesis”. De Meyer R, Gorbanev Y, Ciocarlan R-G, Cool P, Bals S, Bogaerts A, Chemical Engineering Journal 488, 150838 (2024). http://doi.org/10.1016/j.cej.2024.150838
Abstract: Plasma catalysis is a rapidly growing field, often employing a packed-bed dielectric barrier discharge plasma reactor. Such dielectric barrier discharges are complex, especially when a packing material (e.g., a catalyst) is introduced in the discharge volume. Catalysts are known to affect the plasma discharge, though the underlying mechanisms influencing the plasma physics are not fully understood. Moreover, the effect of the catalysts on the plasma discharge and its subsequent effect on the overall performance is often overlooked. In this work, we deliberately design and synthesize catalysts to affect the plasma discharge in different ways. These Ni or Co alumina-based catalysts are used in plasma-catalytic dry reforming of methane and ammonia synthesis. Our work shows that introducing a metal to the dielectric packing can affect the plasma discharge, and that the distribution of the metal is crucial in this regard. Further, the altered discharge can greatly influence the overall performance. In an atmospheric pressure dielectric barrier discharge reactor, this apparently more uniform plasma yields a significantly better performance for ammonia synthesis compared to the more conventional filamentary discharge, while it underperforms in dry reforming of methane. This study stresses the importance of analyzing the plasma discharge in plasma catalysis experiments. We hope this work encourages a more critical view on the plasma discharge characteristics when studying various catalysts in a plasma reactor.
Keywords: A1 Journal Article; Gas conversion Dry reforming of methane Ammonia Microdischarges Dielectric barrier discharge; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ;
Impact Factor: 15.1
DOI: 10.1016/j.cej.2024.150838
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“EPXMA survey of shelf sediments (Southern Bight, North Sea): a glance beyond the XRD-invisible”. de Maeyer-Worobiec A, Dekov VM, Laane RWPM, Van Grieken R, Microchemical journal 91, 21 (2009). http://doi.org/10.1016/J.MICROC.2008.07.001
Abstract: Shelf sediments of the southern North Sea, were studied with a microanalytical [electron probe X-ray microanalysis (EPXMA)] and two bulk [X-ray diffraction (XRD) and X-ray fluorescence (XRF)] techniques. The investigation proved that the promptness of the microanalytical method is combined with a reasonable analytical reliability. XRD studies of such a type of sediments with monotonous mineral composition are not able to provide mineralogical information beyond the main well-crystalline minerals and the mineralogical quantitative characteristic of the sediment based on XRD estimations are incorrect. The EPXMA mineralogical interpretations are based on the statistical evaluation of a huge data set (thousands of mineral particles) and provide a rather correct quantitative determination of the main minerals. The comparative EPXMAXRF study revealed that the Al, Si, K, Ca, Fe and to some extent Ti contents estimated by EPXMA are fairly reliable. In this respect the accuracy of the EPXMA-based mineral identification of the pure silicates, pure aluminosilicates, and Al-, Ca-, Fe- and Ti-containing minerals with simple composition is very high. Mg-calcite, augite and apatite determinations are assessed to be correct. The supposed accuracy of the clay mineral determinations is slightly lower (7080%) than that of the other main minerals due to the complex and varying composition of the clays. The identification of XRD-invisible accessory minerals and quantification of their presence in the sediments is an essential advantage of the EPXMA, which makes it a useful approach in tracing the origin of the sediments, the pathways of their transport and the geochemical processes they have undergone. However, the EPXMA has several flaws, which need to be solved in the future sediment investigations: (1) calibration with natural standards is needed in order to provide a higher accuracy of the mineral determinations; (2) any EPXMA study of sediments needs to be secured with XRF examinations of selected samples since EPXMA gives only semi-quantitative information about the abundance of the elements; (3) ultra-thin window EPXMA of low-Z elements has to be used since some of them (O, C) are always present in the main sediment components: silicates, aluminosilicates, carbonates and metal oxyhydroxides; (4) the interpretations of the clay fraction have to be supported with detailed XRD investigations of selected samples, while the mineralogy of the silt and sand fractions needs to be backed up with optical microscopy studies. The information from different analytical techniques (EPXMA with XRFXRD-optical microscopy of selected samples) combined with the knowledge about the most possible minerals in a given environment, would give the most reliable results in studying mineralogical composition of shelf sediments.
Keywords: A1 Journal article; Laboratory Experimental Medicine and Pediatrics (LEMP); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.MICROC.2008.07.001
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“Hybrid core–shell nanoparticles for cell-specific magnetic separation and photothermal heating”. de la Encarnación C, Jungwirth F, Vila-Liarte D, Renero-Lecuna C, Kavak S, Orue I, Wilhelm C, Bals S, Henriksen-Lacey M, Jimenez de Aberasturi D, Liz-Marzán LM, Journal of materials chemistry B : materials for biology and medicine (2023). http://doi.org/10.1039/D3TB00397C
Abstract: Hyperthermia, as the process of heating a malignant site above 42 °C to trigger cell death, has emerged as an effective and selective cancer therapy strategy. Various modalities of hyperthermia have been proposed, among which magnetic and photothermal hyperthermia are known to benefit from the use of nanomaterials. In this context, we introduce herein a hybrid colloidal nanostructure comprising plasmonic gold nanorods (AuNRs) covered by a silica shell, onto which iron oxide nanoparticles (IONPs) are subsequently grown. The resulting hybrid nanostructures are responsive to both external magnetic fields and near-infrared irradiation. As a result, they can be applied for the targeted magnetic separation of selected cell populations – upon targeting by antibody functionalization – as well as for photothermal heating. Through this combined functionality, the therapeutic effect of photothermal heating can be enhanced. We demonstrate both the fabrication of the hybrid system and its application for targeted photothermal hyperthermia of human glioblastoma cells.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 7
Times cited: 1
DOI: 10.1039/D3TB00397C
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“Influence of the deposition method, temperature and deposition time on the corrosion inhibition of lead dodecanoate coatings deposited on lead surfaces”. De Keersmaecker M, De Wael K, Adriaens A, Journal of solid state electrochemistry 17, 1259 (2013). http://doi.org/10.1007/S10008-012-1964-4
Abstract: Electrochemical impedance measurements have been used to investigate the influence of the deposition method, including time and temperature, upon the corrosion inhibition characteristics of lead dodecanoate coatings on lead electrodes. The results were analysed using multivariate statistics and show that, in general, these easily prepared coatings are very protective against corrosion. The temperature proves to be an important parameter for the quality and the corrosion inhibition efficiency of the coating. A comparison between two different electrochemically assisted deposition methods, immersion using a reduction pretreatment and cyclic voltammetry, does not show significant differences. Using the immersion technique at room temperature, the deposition time was tested as the third influencing parameter for the corrosion inhibition efficiency of the deposited lead dodecanoate coatings. A longer deposition time of the lead into the sodium dodecanoate solution provides a layer with a somewhat higher corrosion resistance.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 2.316
Times cited: 4
DOI: 10.1007/S10008-012-1964-4
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“Electrochemical fingerprint of street samples for fast on-site screening of cocaine in seized drug powders”. De Jong M, Sleegers N, Kim J, Van Durme F, Samyn N, Wang J, De Wael K, Chemical science , 1 (2016). http://doi.org/10.1039/C5SC04309C
Abstract: We report on a wearable fingertip sensor for on-the-spot identification of cocaine and its cutting agents in street samples. Traditionally, on-site screening is performed by means of colour tests which are difficult to interpret and lack selectivity. By presenting the distinct voltammetric response of cocaine, cutting agents, binary mixtures of cocaine and street samples in solution and powder street samples, we were able to elucidate the electrochemical fingerprint of all these compounds. The new electrochemical concept holds considerable promise as an on-site screening method.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 8.668
Times cited: 37
DOI: 10.1039/C5SC04309C
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“Unraveling the mechanisms behind the complete suppression of cocaine electrochemical signals by chlorpromazine, promethazine, procaine, and dextromethorphan”. De Jong M, Sleegers N, Florea A, Van Loon J, van Nuijs ALN, Samyn N, De Wael K, Analytical chemistry 91, 15453 (2019). http://doi.org/10.1021/ACS.ANALCHEM.9B03128
Abstract: The present work investigates the challenges accompanied by the electrochemical cocaine detection in physiological conditions (pH 7) in the presence of chlorpromazine, promethazine, procaine, and dextromethorphan, frequently used cutting agents in cocaine street samples. The problem translates into the absence of the cocaine oxidation signal (signal suppression) when in a mixture with one of these compounds, leading to false negative results. Although a solution to this problem was provided through earlier experiments of our group, the mechanisms behind the suppression are now fundamentally investigated via electrochemical and liquid chromatography quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS) strategies. The latter was used to confirm the passivation of the electrodes due to their interaction with promethazine and chlorpromazine. Electron transfer mechanisms were further identified via linear sweep voltammetry. Next, adsorption experiments were performed on the graphite screen printed electrodes both with and without potential assistance in order to confirm if the suppression of the cocaine signals is due to passivation induced by the cutting agents or their oxidized products. The proposed strategies allowed us to identify the mechanisms of cocaine suppression for each cutting agent mentioned. Suppression due to procaine and dextromethorphan is caused by fouling of the electrode surface by their oxidized forms, while for chlorpromazine and promethazine the suppression of the cocaine signal is related to the strong adsorption of these (nonoxidized) cutting agents onto the graphite electrode surface. These findings provide fundamental insights in possible suppression and other interfering mechanisms using electrochemistry in general not only in the drug detection sector.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre; Product development
Impact Factor: 6.32
DOI: 10.1021/ACS.ANALCHEM.9B03128
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“Tackling poor specificity of cocaine color tests by electrochemical strategies”. De Jong M, Florea A, Eliaerts J, Van Durme F, Samyn N, De Wael K, Analytical chemistry 90, 6811 (2018). http://doi.org/10.1021/ACS.ANALCHEM.8B00876
Abstract: This paper presents electrochemical strategies for the fast screening of cocaine and most common cutting agents found in seized drug samples. First, a study on the performance of Scott color tests on cocaine and a wide range of cutting agents is described. The cutting agents causing false positive or false negative results when in mixture with cocaine are identified. To overcome the lack of specificity of color tests, we further propose a fast screening strategy by means of square wave voltammetry on disposable graphite screen printed electrodes, which reveals the unique fingerprint of cocaine and cutting agents. By employing a forward and backward scan and by a dual pH strategy, we enrich the electrochemical fingerprint and enable the simultaneous detection of cocaine and cutting agents. The effectiveness of the developed strategies was tested for the detection of cocaine in seized cocaine samples and compared with the color tests. Moreover, we prove the usefulness of square wave voltammetry for predicting possible interfering agents in color tests, based on the reduction peak of cobalt thiocyanate. The developed electrochemical strategies allow for a quick screening of seized cocaine samples resulting in a selective identification of drugs and cutting agents.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 6.32
Times cited: 7
DOI: 10.1021/ACS.ANALCHEM.8B00876
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“Levamisole : a common adulterant in cocaine street samples hindering electrochemical detection of cocaine”. De Jong M, Florea A, de Vries A-M, van Nuijs ALN, Covaci A, Van Durme F, Martins JC, Samyn N, De Wael K, Analytical chemistry 90, 5290 (2018). http://doi.org/10.1021/ACS.ANALCHEM.8B00204
Abstract: The present work investigates the electrochemical determination of cocaine in the presence of levamisole, one of the most common adulterants found in cocaine street samples. Levamisole misleads cocaine color tests, giving a blue color (positive test) even in the absence of cocaine. Moreover, the electrochemical detection of cocaine is also affected by the presence of levamisole, with a suppression of the oxidation signal of cocaine. When levamisole is present in the sample in ratios higher than 1:1, the cocaine signal is no longer detected, thus leading to false negative results. Mass spectrometry and nuclear magnetic resonance were used to investigate if the signal suppression is due to the formation of a complex between cocaine and levamisole in bulk solution. Strategies to eliminate this suppressing effect are further suggested in this manuscript. In a first approach, the increase of the pH of the sample solution from pH 7 to pH 12 allowed the voltammetric determination of cocaine in the presence of levamisole in a concentration range from 10 to 5000 μM at nonmodified graphite disposable electrodes with a detection limit of 5 μM. In a second approach, the graphite electrode was cathodically pretreated, resulting in the presence of oxidation peaks of both cocaine and levamisole, with a detection limit for cocaine of 3 μM over the linear range of concentrations from 10 to 2500 μM. Both these strategies have been successfully applied for the simultaneous detection of cocaine and levamisole in three street samples on unmodified graphite disposable electrodes.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre
Impact Factor: 6.32
Times cited: 8
DOI: 10.1021/ACS.ANALCHEM.8B00204
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“Characterization of oxide precipitates in heavily B-doped silicon by infrared spectroscopy”. de Gryse O, Clauws P, Vanhellemont J, Lebedev OI, van Landuyt J, Simoen E, Claeys C, Journal of the electrochemical society 151, G598 (2004). http://doi.org/10.1149/1.1776592
Abstract: Infrared absorption spectra of oxygen precipitates in boron-doped silicon with a boron concentration between 10(17) and 10(19) cm(-3) are analyzed, applying the spectral function representation of composite materials. The aspect ratio of the platelet precipitates is determined by transmission electron microscopy measurements. The analysis shows that in samples with moderate doping levels (<10(18) B cm(-3)) SiOγ precipitates are formed with the same composition as in the lightly doped case. In the heavily boron-doped (>10(18) cm(-3)) samples, however, the measured spectra of the precipitates are consistent with a mixture of SiO2 and B2O3, with a volume fraction of B2O3 as high as 0.41 in the most heavily doped case. (C) 2004 The Electrochemical Society.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 3.259
Times cited: 13
DOI: 10.1149/1.1776592
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“Parameter evaluation for the analysis of oxide-based samples with radio ferquency glow discharge mass spectrometry”. de Gendt S, Van Grieken RE, Ohorodnik SK, Harrison WW, Analytical chemistry 67, 1026 (1995). http://doi.org/10.1021/AC00102A002
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1021/AC00102A002
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“Gaining new insight into low-temperature aqueous photochemical solution deposited ferroelectric PbTiO3 films”. De Dobbelaere C, Lourdes Calzada M, Bretos I, Jimenez R, Ricote J, Hadermann J, Hardy A, Van Bael MK, Materials chemistry and physics 174, 28 (2016). http://doi.org/10.1016/J.MATCHEMPHYS.2016.02.047
Abstract: The nature of the low-temperature photochemical assisted formation process of ferroelectric lead titanate (PbTiO3) films is studied in the present work. Films are obtained by the deposition of an aqueous solution containing citric acid based (citrato) metal ion complexes with intrinsic UV activity. This UV activity is crucial for the aqueous photochemical solution deposition (aqueous PCSD) route being used. UV irradiation enhances the early decomposition of organics and results in improved electrical properties for the crystalline oxide film, even if the film is crystallized at low temperature. GATR-FTIR shows that UV irradiation promotes the decomposition of organic precursor components, resulting in homogeneous films if applied in the right temperature window during film processing. The organic content, morphology and crystallinity of the irradiated films, achieved at different processing atmospheres and temperatures, is studied and eventually correlated to the functional behavior of the obtained films. This is an important issue, as crystalline films obtained at low temperatures often lack ferroelectric responses. In this work, the film prepared in pure oxygen at the very low temperature of 400 degrees C and after an optimized UV treatment presents a significant remanent polarization value of P-r = 8.8 mu C cm(-2). This value is attributed to the better crystallinity, the larger grain size and the reduced porosity obtained thanks to the early film crystallization effectively achieved through the UV treatment in oxygen. (C) 2016 Elsevier B.V. All rights reserved.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 2.084
Times cited: 4
DOI: 10.1016/J.MATCHEMPHYS.2016.02.047
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“Molecular sieve properties of mesoporous silica with intraporous nanocarbon”. de Clippel F, Harkiolakis A, Ke X, Vosch T, Van Tendeloo G, Baron GV, Jacobs PA, Denayer JFM, Sels BF, Chemical communications 46, 928 (2010). http://doi.org/10.1039/b918864a
Abstract: Biporous carbonsilica materials (CSM) with molecular sieve properties and high sorption capacity were developed by synthesizing nano-sized carbon crystallites in the mesopores of Al-MCM-41.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Impact Factor: 6.319
Times cited: 21
DOI: 10.1039/b918864a
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“Single particle analysis of aerosols, observed in the marine boundary layer during the Monterey Area Ship Tracks Experiment (MAST), with respect to cloud droplet formation”. de Bock LA, Joos PE, Noone KJ, Pockalny RA, Van Grieken RE, Journal of atmospheric chemistry 37, 299 (2000). http://doi.org/10.1023/A:1006416600722
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1023/A:1006416600722
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“Micro-analysis of individual aerosol particles using electron, proton and laser beams”. de Bock LA, Jambers W, Van Grieken RE, South African journal of chemistry = Suid-Afrikaanse tydskrif vir chemie 49, 65 (1996)
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“The Dominant Pathways for the Conversion of Methane into Oxygenates and Syngas in an Atmospheric Pressure Dielectric Barrier Discharge”. De Bie C, van Dijk J, Bogaerts A, The journal of physical chemistry: C : nanomaterials and interfaces 119, 22331 (2015). http://doi.org/10.1021/acs.jpcc.5b06515
Abstract: A one-dimensional fluid model for a dielectric barrier discharge in CH4/O2 and CH4/CO2 gas mixtures is developed. The model describes the gas-phase chemistry for partial oxidation and for dry reforming of methane. The spatially averaged densities of the various plasma species are presented as a function of time and initial gas mixing ratio. Besides, the conversion of the inlet gases and the selectivities of the reaction products are calculated. Syngas, higher hydrocarbons, and higher oxygenates are typically found to be important reaction products. Furthermore, the main underlying reaction pathways for the formation of syngas, methanol, formaldehyde, and other higher oxygenates are determined.
Keywords: A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4.536
Times cited: 46
DOI: 10.1021/acs.jpcc.5b06515
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