Article
Chemistry, Multidisciplinary
Iris Berg, Luca Schio, Justus Reitz, Elena Molteni, Linoy Lahav, Carolina Gutierrez Bolanos, Andrea Goldoni, Cesare Grazioli, Guido Fratesi, Max M. Hansmann, Luca Floreano, Elad Gross
Summary: In this study, the self-assembly of N-heterocyclic olefins (NHOs) on gold surface was investigated using experimental and computational methods. It was found that NHOs can self-assemble into dimers, trimers, and tetramers, forming stable monolayers. The study also revealed that NHOs can adsorb on gold surface in a flat-lying geometry through coordination with gold adatoms, and the surface interaction can be further increased by functionalizing the backbone with methyl groups, leading to enhanced thermal stability and impact on work-function values.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Gwendolynne L. Lee, Thomas Chan, Joseph M. Palasz, Clifford P. Kubiak
Summary: A method for the synthesis of electrode-attached Rh(I) diisocyanide coordination polymers that allows for high control of film thickness has been reported. The films showed improved chemical stability and electrochemical stability, making them suitable for various electrochemical applications.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Sicheon Seong, Hungu Kang, Seulki Han, Young Ji Son, Jiung Jang, Hyo Jae Yoon, Shoichi Maeda, Subin Song, Debabrata Palai, Tomohiro Hayashi, Jaegeun Noh
Summary: The formation and surface structure of pentafluorobenzeneselenolate (PFB-Se) self-assembled monolayers (SAMs) on Au(111) were examined by scanning tunneling microscopy (STM). Results showed that the structural order of the SAMs was improved by vapor deposition compared to solution deposition. Kelvin probe force microscopy measurements exhibited a significant difference in the work function between pentafluorobenzenethiolate and PFB-Se SAMs due to their different domain and packing structures.
SURFACES AND INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Jakob Genser, Daniele Nazzari, Viktoria Ritter, Ole Bethge, Kenji Watanabe, Takashi Taniguchi, Emmerich Bertagnolli, Friedhelm Bechstedt, Alois Lugstein
Summary: Silicene shows promising potential for high-performance devices due to its unique electronic and optical properties, but its outstanding characteristics are not preserved on certain growth templates.
Article
Chemistry, Inorganic & Nuclear
Finn Petersen, Irene Lautenschlager, Alexander Schlimm, Benedikt M. Floser, Hanne Jacob, Reihaneh Amirbeigiarab, Talina R. Rusch, Thomas Strunskus, Olaf Magnussen, Felix Tuczek
Summary: Transition metal complexes are important for small molecule activation and electrocatalysis. By covalently attaching a molybdenum tricarbonyl complex supported by a tripodal phosphine ligand to a metallic surface, the study successfully combined homogeneous catalysts with metallic surfaces. The resulting self-assembled monolayer was characterized and the vibrational properties of the surface-adsorbed complexes were analyzed using multiple techniques.
DALTON TRANSACTIONS
(2021)
Article
Multidisciplinary Sciences
Alex Inayeh, Ryan R. K. Groome, Ishwar Singh, Alex J. Veinot, Felipe Crasto de Lima, Roberto H. Miwa, Cathleen M. Crudden, Alastair B. McLean
Summary: N-heterocyclic carbenes (NHCs) have emerged as a promising alternative to sulfur-based ligands for self-assembly on gold surfaces, but there are still many unanswered questions about their behavior on surfaces. This study examines fundamental questions such as NHC orientation, mobility, and self-assembly by analyzing NHC overlayers on Au(111).
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Physical
John C. Thomas, Antonio Rossi, Darian Smalley, Luca Francaviglia, Zhuohang Yu, Tianyi Zhang, Shalini Kumari, Joshua A. Robinson, Mauricio Terrones, Masahiro Ishigami, Eli Rotenberg, Edward S. Barnard, Archana Raja, Ed Wong, D. Frank Ogletree, Marcus M. Noack, Alexander Weber-Bargioni
Summary: This study investigates the impact of individual atomic defects on the macroscopic functionality of 2D materials using intelligent hyperspectral scanning tunneling spectroscopy (STS) mapping. By utilizing machine learning methods, the researchers autonomously collect and analyze spectroscopic data, and provide a customizable workflow for experimental decision-making. The results demonstrate the potential of artificial intelligence in hyperspectral STS mapping.
NPJ COMPUTATIONAL MATERIALS
(2022)
Article
Chemistry, Physical
Natalia D. Aagaard, Eugenia Zelaya, Mariano H. Fonticelli, Julio C. Azcarate
Summary: A quantitative X-ray photoelectron spectroscopy study was conducted on the electron-induced degradation of self-assembled monolayers of n-dodecanethiol on Au(100) and Au(111), revealing that despite differences in the most abundant damaging products on the surfaces, organic material desorbs at comparable rates from both single-crystalline surfaces. The study also provided arguments based on the reaction mechanism to describe the cross-linking of hydrocarbon chains and explain the similar desorption rates of sulfur-containing species from both surfaces.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Andika Asyuda, Saunak Das, Michael Zharnikov
Summary: The thermal stability of archetypical alkanethiolate and aromatic thiolate self-assembled monolayers on gold surfaces was studied, showing stability at certain temperatures followed by molecular desorption and decomposition. The degradation was mainly due to the cleavage of C-S bonds, impacting the overall stability of the monolayers.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Physical
Richard K. Berger, Andreas Jeindl, Lukas Hoermann, Oliver T. Hofmann
Summary: Organic adlayers on inorganic substrates can form two-dimensional metal-organic frameworks due to the incorporation of adatoms. This study uses density functional theory to investigate the incorporation of native adatoms within molecular adlayers on Au(111). The results provide insights into the changes in adsorption geometry and energy induced by adatoms.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Multidisciplinary
Philip N. Jemmett, David C. Milan, Richard J. Nichols, Liam R. Cox, Sarah L. Horswell
Summary: Lipid bilayers are essential to the function of biological cell membranes, with their structure and function varying depending on the constituent molecules. This study focused on the electrochemical phase behavior of DPPC, a glycerophospholipid commonly found in nature, and found that even subtle changes in molecular structure can significantly impact a membrane's response to its environment.
Article
Chemistry, Physical
Deb Kumar Bhowmick, Adrian Joe Urban, Manfred Bartsch, Bjoern Braunschweig, Helmut Zacharias
Summary: Efficient control of interface chemistry enables better tunability of electronic properties, and a novel near-UV-initiated direct modification method has been demonstrated to form stable organic monolayers on silicon surfaces with high hydrolytic stability.
JOURNAL OF PHYSICAL CHEMISTRY C
(2022)
Article
Chemistry, Physical
Mathias Piescheck, Areeg Abdelrahman, Johannes M. Hermann, Heiko Mueller, Timo Jacob, Ludwig A. Kibler
Summary: The investigation reveals that the 4-mercaptopyridine molecules do not catalyze HPOR, but after metallization with Pt, the Pt islands can recover catalytic activity for the reaction, showing a gradual decrease in current density contribution from Au to Pt.
Article
Chemistry, Physical
Waleed Azzam, Abdu Subaihi, Michael Rohwerder, Michael Zharnikov, Asif Bashir
Summary: In this study, self-assembled monolayers of 4-fluorobenzenemethanethiol on a gold surface were characterized using scanning tunneling microscopy. A highly ordered monolayer with a commensurate structure was observed, and individual spots corresponding to different components of the monolayer were successfully resolved. These results demonstrate the potential of STM for imaging densely packed molecular assemblies.
Article
Biochemistry & Molecular Biology
Young Ji Son, Jin Wook Han, Hungu Kang, Sicheon Seong, Seulki Han, Shoichi Maeda, Shunta Chikami, Tomohiro Hayashi, Masahiko Hara, Jaegeun Noh
Summary: We investigated the surface structure, binding conditions, electrochemical behavior, and thermal stability of self-assembled monolayers (SAMs) on Au(111) formed by N-(2-mercaptoethyl)heptanamide (MEHA) using scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV). The STM study revealed structural transitions of MEHA SAMs on Au(111) depending on deposition time, from a liquid phase to a closely packed beta-phase. XPS measurements showed increased chemisorbed sulfur and rearrangement of molecular backbones in the well-ordered beta-phase formed after a longer deposition period of 1 hour. CV results showed significant differences in electrochemical behavior between MEHA and decanethiol (DT) SAMs due to the presence of an internal amide group in MEHA SAMs.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Review
Chemistry, Analytical
Celeste R. Rousseau, Philippe Buhlmann
Summary: Research in recent years has focused on the development of solid-contact ISEs for calibration-free measurements in long-term, in situ analysis. This review discusses the definition of calibration-free usage and relevant literature, with a focus on different mechanisms of ion-to-electron signal transduction and different types of transduction modes.
TRAC-TRENDS IN ANALYTICAL CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Evan L. Anderson, Blair K. Troudt, Philippe Buhlmann
Summary: As solid-contact potentiometric sensors gain more attention, it becomes clear that traditional reference electrode designs are no longer suitable for new challenging applications. Maintaining a constant interface with the sample through a salt bridge is crucial for avoiding contamination of the reference electrode.
Article
Chemistry, Analytical
Kwangrok R. Choi, Xin Chen, Jinbo Hu, Philippe Buhlmann
Summary: The study demonstrated the use of plasticizer-free and cross-linked poly(decyl methacrylate) matrix to improve sensor lifetime. Covalently attached H+ ionophores or ionic sites in ISEs showed quick responses to pH and high selectivity, with superior properties compared to conventional PVC-based ISEs in various environments.
ANALYTICAL CHEMISTRY
(2021)
Article
Chemistry, Analytical
Celeste R. Rousseau, Madeline L. Honig, Philippe Buhlmann
Summary: This study explored the stability of solid-contact ion-selective electrodes by controlling the potential variations between electrodes using different membranes and redox buffers. The reproducibility and long-term drift of the electrodes were assessed with varying results depending on the membrane type used.
ANALYTICAL CHEMISTRY
(2022)
Article
Chemistry, Organic
Blair K. Troudt, John W. Vue, Philippe Buhlmann
Summary: Analytical techniques for detecting aldehydes often involve reactions with hydrazine or hydroxylamine derivatives. This study used H-1 NMR spectroscopy to investigate the reaction kinetics of aromatic and aliphatic aldehydes with phenylhydrazine or O-phenylhydroxylamine. The results indicate that hydrazone formation is 71 times faster than oxime formation.
Review
Chemistry, Physical
Xin Chen, Philippe Buhlmann
Summary: Ion-selective electrodes (ISEs) are widely used in clinical chemistry analyzers, but there is increasing interest in paper-based devices, wearable and implantable sensors, and other miniaturized ISEs. This review focuses on the development of suitable polymeric matrixes for ISEs and highlights the benefits of silicone materials as alternative matrixes with enhanced biocompatibility. The review also discusses specific types of silicones and their applications in ISEs, providing valuable information for future research efforts.
CURRENT OPINION IN ELECTROCHEMISTRY
(2022)
Article
Chemistry, Analytical
Eliza J. Herrero, Blair K. Troudt, Philippe Buhlmann
Summary: This study investigates the lower limits of detection (LODs) for paper-based sensors using AgCl/Ag transducers. The contamination of Cl- from device materials significantly increases the chloride concentration in paper-contained samples, worsening the lower LODs. Additionally, the hypothesis of metal cation adsorption onto filter paper does not significantly affect the performance of AgCl/Ag transducers.
ANALYTICAL CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Nyssa S. S. Capman, Xue Zhen, Justin T. Nelson, V. R. Saran Kumar Chaganti, Raia C. Finc, Michael J. Lyden, Thomas L. Williams, Mike Freking, Gregory J. Sherwood, Philippe Buhlmann, Christopher J. Hogan, Steven J. Koester
Summary: Rapid detection of volatile organic compounds (VOCs) using graphene-based variable capacitor arrays has been demonstrated in this study. This versatile material allows for selective and rapid detection of multiple VOCs at different concentrations. Machine learning methods achieved high accuracy in classifying the VOCs.
Article
Nanoscience & Nanotechnology
Baoyue Fan, Brian D. Spindler, Wenyang Zhao, Hoffman Chan, Zhao Wang, Minog Kim, Yevedzo Chipangura, Philippe Buhlmann, Andreas Stein
Summary: The glucose sensitivity of copper(II) oxide particles with different morphologies (spheres, platelets, and needles) for nonenzymatic glucose sensors was investigated. The CuO nanoparticles were synthesized with different parameters to control their morphology. The study revealed that the grain size of copper oxide nanoparticles and the introduced capacitance played a major role in the electrocatalytic performance of glucose sensing. Needle-shaped CuO nanoparticles showed the best sensitivity, with a linear range of 0.05-5 mM glucose and excellent long-term stability. This work provides insight into the potential use of CuO-based materials in biosensors and the contributing factors of metal oxide-based nanoparticles in sensing applications.
ACS APPLIED NANO MATERIALS
(2023)
Editorial Material
Chemistry, Analytical
Eric Bakker, Philippe Buhlmann, J. Justin Gooding, Robert E. Gyurcsanyi, Ernoe Pretsch
Article
Chemistry, Multidisciplinary
Xin I. N. Dong, Brian D. Spindler, Minog Kim, Andreas Stein, Philippe Bu''hlmann
Summary: This study reveals the nanopore-driven sequestration of ionic liquids from a silicone membrane, a phenomenon that has not been reported before. Reference electrodes with ionic liquid-doped PDMS reference membranes and colloid-imprinted mesoporous carbon as solid contact are nonfunctional unless the porosity of the solid contact is properly addressed. Pre-saturation of the carbon with ionic liquid or increasing the amount of ionic liquid in the membrane solution can overcome this depletion issue.
Article
Chemistry, Analytical
Brian D. Spindler, Katerina I. Graf, Xin I. N. Dong, Minog Kim, Xin V. V. Chen, Philippe Buhlmann, Andreas Stein
Summary: This study investigated the biocompatibility and resistance to biofouling of solid-contact selective electrodes (SC-ISEs) in direct long-term contact with physiological samples. K+ SC-ISEs were prepared using three different condensation-cured silicones and exhibited excellent selectivity and low signal drift. The results demonstrate the suitability of these electrodes for use in physiological samples.
ANALYTICAL CHEMISTRY
(2023)
Article
Engineering, Chemical
Austin J. Andrews, Philippe Buhlmann, Christopher J. Hogan
Summary: Ion selective electrodes (ISEs) are used to measure the phase boundary potential at the surface of a sensing membrane, but the influence of fluid flow on ISEs is not well studied. This study developed a numerical model to investigate the impact of external flow on the ISE membrane and aqueous sample interface, and found that flow distortion can increase the phase boundary potential.
CHEMICAL ENGINEERING SCIENCE
(2023)
Review
Chemistry, Analytical
Blair K. Troudt, Celeste R. Rousseau, Xin I. N. Dong, Evan L. Anderson, Philippe Buhlmann
Summary: This review discusses the deficiencies of commonly used reference electrodes and highlights recent research work on the development of new reference electrode designs for more stable and reliable electrochemical experiments, including salt-bridge reference electrodes with nanoporous and capillary junctions, solid-contact reference electrodes, and ionic liquid-based reference electrodes.
ANALYTICAL SCIENCES
(2022)
Article
Chemistry, Analytical
Eliza J. Herrero, Philippe Buhlmann
Summary: The study introduces potentiometric sensors fully integrated into knitted polyester fabric and their application in aqueous and biological samples, demonstrating their potential for improved detection limits. Research on the penetration of polyester yarns reveals the impact of pore structure on sensor fabrication and performance.
ANALYSIS & SENSING
(2021)