Antonella Badia

• BSc, PhD
• Professor (Full) at Université de Montréal

Antimicrobial peptides, such as GL13K, have a high binding selectivity toward bacterial membranes, while not affecting healthy mammalian cells at therapeutic concentrations. However, delivery of these peptides is challenging since they are susceptible to proteolytic hydrolysis and exhibit poor cellular uptake. A protective nanocarrier is thus propo...

The cover image is based on the Original Article Experimental methods in chemical engineering: Atomic force microscopy – AFM by Patricia Moraille et al., https://doi.org/10.1002/cjce.24407.

Cells sense and respond to mechanical cues from the surrounding substrate through filopodia. Regulation of cellular biomechanics operates at the nanoscale. Therefore, a better understanding of the relationship between filopodia and nanoscale surface features is highly relevant for the rational development of implant surfaces. The objective of this...

Large-area metal/molecule/metal junctions based on self-assembled monolayers (SAMs) of organothiolates are of interest for investigations of charge transport across ultrathin organic films and the fabrication of molecular electronic devices. Several recent reports demonstrate an odd-even dependency in the rate of charge transport through SAMs of th...

Elucidating the influence of the monolayer interface versus bulk on the macroscopic properties (e.g., surface hydrophobicity, charge transport, and electron transfer) of organic self-assembled monolayers (SAMs) chemically anchored to metal surfaces is a challenge. This article reports the characterization of prototypical SAMs of n-alkanethiolates o...

Large-area metal/molecule/metal junctions based on self-assembled monolayers (SAMs) of organothiolates are of interest for the investigation of charge transport across ultrathin organic films and the fabrication of molecular electronic devices such as diodes and switches. Several reports demonstrate an odd-even dependency in the rate of charge tran...

We have evaluated the response to nanotopography of CHO-K1 cells that express wild-type paxillin or paxillin with mutations at serine 273 that inhibit phosphorylation. Cells were grown on nanoporous and polished titanium surfaces. With all cell types, immunofluorescence showed that adhesion and spreading were minimally affected on the treated surfa...

The ability of organic self-assembled monolayers (SAMs) to act as insulating barriers to charge and ion transport or molecular diffusion is critical to their application in a variety of technologies. The use of appropriate analytical tools to characterize the dielectric properties of these molecular thin films is important for the control of struct...

This article describes the use of a redox-induced ion-pairing reaction confined to an electrode surface to detect the micellar aggregation of ionic surfactants in water. Cyclic voltammetry characterizes the Faradaic response of self-assembled monolayers (SAMs) of ferrocenyldodecanethiolate on gold in aqueous solutions of the sodium salts of the ani...

Lithium-ion is currently the leading technology for electrochemical energy storage, especially in the transportation sector. The electrification of vehicles through the use of lithium-ion batteries (LiBs) is at the center of the world efforts to decrease atmospheric pollution by reducing CO 2 emission. Due to the high efficiency of electrical motor...

Lithium-ion is currently the leading technology for electrochemical energy storage, especially in the transportation sector. The electrification of vehicles through the use of lithium-ion batteries (LiBs) is at the center of the world efforts to decrease atmospheric pollution by reducing CO 2 emission. Due to the high efficiency of electrical motor...

The development of advanced Li-ion battery would require innovative approaches to improve the present performances, while lowering the environmental footprint and price of their fabrication. In this scope, we are currently carrying out different projects to consider the electrode materials as well the process to make the batteries. This presentatio...

The interaction of nanoparticles (NPs) with pulmonary surfactant is important for understanding the potential adverse effects of inhaled engineered and incidental nanomaterials. The effects of a low concentration (0.001 wt%) of charged hydrophilic silica NPs of hydrodynamic diameter of ~20 nm on the phase behavior and lateral structure of lipid-onl...

Microcantilever transducers can be valuable tools for the investigation of physicochemical processes in organized molecular films. Gold-coated cantilevers are used here to investigate the electrochemomechanical behavior of redox-active self-assembled monolayers (SAMs) of ferrocenylalkanethiolates (Fc(CH2)nS) of different alkyl chain lengths. A sign...

The effect of low concentration (0.001 wt%) of charged silica nanoparticles (NPs) on the molecular structure of lung surfactant monolayers was investigated at the air/water interface using grazing incidence X-ray diffraction (GIXD) and X-ray reflectivity (XR). The lipid systems investigated included 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC...

The resurgence of the lithium metal battery requires innovations in technology, including the use of non-conventional liquid electrolytes. The inherent electrochemical potential of lithium metal (-3.04 V vs SHE) inevitably limits its use in many solvents, such as acetonitrile, which could provide electrolytes with increased conductivity. The aim of...

The resurgence of the lithium metal battery requires innovations in technology, including the use of non-conventional liquid electrolytes. The inherent electrochemical potential of lithium metal (-3.04 V vs SHE) inevitably limits its use in many solvents, such as acetonitrile, which could provide electrolytes with increased conductivity. The aim of...

Subtle conformational-based distinctions in the supramolecular structure of self-assembled monolayers (SAMs) of ω-ferrocenylalkanethiolates on gold (FcCnSAu) have been shown to significantly impact their electrical and redox properties. We investigate the effect of differences in the intermolecular van der Waals interactions and molecular packing e...

Statement of significance: Oxidative patterning was applied to nanosculpture a unique three-dimensional network of nanopores on titanium surfaces. Our study illustrates how such facile treatment can be advantageously used to modulate cellular behavior. The nanoscale lateral protrusions on filopodia elicited by this surface are novel adhesive struc...

The interfacial electrochemistry of self-assembled monolayers (SAMs) of ferrocenyldodecanethiolate on gold (FcC12SAu) electrodes is applied to detect the micellization of some common anionic surfactants, sodium n-alkyl sulfates, sodium n-alkyl sulfonates, sodium diamyl sulfosuccinate, and sodium dodecanoate, in aqueous solution by cyclic voltammetr...

The redox-induced pairing from aqueous solution of a homologous series of sodium n-alkyl sulfate (NaCnSO4) surfactants of 6, 8, 10, and 12 carbons with gold-tethered self-assembled monolayers (SAMs) of ferrocenyldodecanethiolate (FcC12SAu) is investigated by cyclic voltammetry combined with surface plasmon resonance (SPR) spectroscopy. The adsorbed...

Planar-supported phospholipid bilayers are increasingly used as synthetic membranes for scientific and practical applications. The thermotropic phase properties of supported bilayers are important for recreating biologically relevant situations. Unlike free-standing lipid membranes which undergo one gel-to-fluid or main phase transition, mica-suppo...

The redox-activated deflection of microcantilevers has attracted interest for nanoactuation and chemical sensing. Microcantilever sensors are devices that transduce (bio)chemical reactions into a quantifiable nanomechanical motion via surface stress changes. Despite promising applications in analytical science, poor signal-to-noise ratios and a lim...

Oxidoreduction of self-assembled monolayers (SAMs) of ferrocenyldodecanethiolate on gold in aqueous solutions of surface-active sodium n-alkyl sulfates (NaCnSO4) of 6, 8, 10, and 12 carbons is investigated by cyclic voltammetry and surface plasmon resonance. The effects of surfactant micellization and alkyl chain length on the redox response of the...

The interfacial electrochemistry of self-assembled monolayers of ferrocenyldodecanethiolate on gold electrodes in aqueous solutions of the anionic surfactants sodium n-hexyl sulfate and sodium n-dodecyl sulfate is reported. The effects of surfactant micellization and alkyl chain length on the redox potential of the monolayer-bound ferrocene are exa...

This contribution offers a comprehensive understanding of the factors that govern the morphologies of Langmuir-Blodgett (LB) monolayers of amphiphilic diblock copolymers (BCs). This is achieved by a detailed investigation of a wide range of polystyrene-poly(4-vinyl pyridine) (PS-P4VP) block copolymers, in contrast to much more limited ranges in pre...

A popular instrument configuration for the fast tracking of the resonance angle position during time-dependent surface plasmon resonance (SPR) measurements uses stationary optics, a convergent or divergent fan-shaped beam from a light source of finite spectral bandwidth, and an array photodetector to simultaneously cover a range of incident angles....

We report the formation of lipid membranes supported by a soft polymeric cushion of polydopamine. First, 20 nm thick polydopamine films were formed on mica substrates. Atomic force microscopy imaging indicated that these films were also soft with a surface roughness of 2 nm under hydrated conditions. A zwitterionic phospholipid bilayer was then dep...

The effect of hydrophobic alkylated gold nanoparticles (Au NPs) on the phase behavior and structure of Langmuir monolayers of dipalmitoylphosphatidylcholine (DPPC) and Survanta, a naturally derived commercial pulmonary surfactant that contains DPPC as the main lipid component and hydrophobic surfactant proteins SP-B and SP-C, has been investigated...

Understanding and controlling the processes in block copolymer (BC) monolayers at the air/water interface during surface area compression is a key issue for producing ultrathin films of predetermined morphology with well-defined order and known dimensions. Langmuir isotherms of nanodot-forming BC monolayers generally display a plateau indicative of...

The electrochemically-activated deflection of free-standing microcantilevers has received considerable interest for chemical sensing and nanoactuation. The development and optimization of this type of microcantilever transduction still requires a molecular-level understanding of the surface stress changes that cause the cantilever to bend. We prese...

The redox-activated deflection of microcantilevers has attracted interest for chemical sensing and nanoactuation. However, the development and optimization of this type of microcantilever transduction requires a better understanding of the effect of the particular system parameters on the surface stress changes that cause the measured bending respo...

Metal-reactive organosulfur groups were patterned onto mica and silicon surfaces by dewetting instabilities during the Langmuir-Blodgett (LB) deposition of phase-separated mixed phospholipid monolayers. Monolayers were formed from binary mixtures of dipalmitoylphosphatidylcholine (DPPC), dilauroylphosphatidylcholine (DLPC), and their ω-methyldisulf...

Langmuir-Blodgett monolayers consisting of a network of nanostrands have occasionally been reported in the literature, but are often coexistent with other morphologies, which is not useful for potential applications. With the use of PS-P4VP/PDP, a polystyrene-poly(4-vinyl pyridine) diblock copolymer of 12 mol % VP content mixed with 3-pentadecylphe...

Two new silver(I)–dithioether coordination polymers based on the self-assembly of the dithioether ligands L n −R = CH3–S(CH2)n S–CH3 (n = 1, 3) and AgX silver salts, where X = ClO4− (1) and PF6− (2), have been synthesized and characterized by single crystal X-ray diffraction and TGA. The crystallographic data of those complexes are: (1) Monoclinic...

The electrochemically induced motion of free-standing microcantilevers is attracting interest as micro/nanoactuators and robotic devices. The development and implementation of these cantilever-based actuating technologies requires a molecular-level understanding of the origin of the surface stress that causes the cantilever to bend. Here, we report...

This review describes a simple high-throughput method for producing laterally nanostructured monolayer and bilayer films on planar surfaces based on the Langmuir-Blodgett transfer of a phase-separated phospholipid mixture from the air/water interface to a solid support. Applications of the patterned lipid films to spatially direct the adsorption of...

Atomic force microscopy was used to image Bacillus thuringiensis (Bt) toxins interacting with their natural targets, Manduca sexta midgut brush border membranes (BBMs), as well as with dipalmitoylphosphatidylcholine-dioleoylphosphatidylcholine (DPPC-DOPC) solid-supported lipid bilayers. In lipid bilayers, Cry1Aa formed structures 30-60 nm wide and...

The miscibility of the solid-phase-forming distearoylphosphatidylcholine (DSPC) and the fluid-phase-forming dilauroylphosphatidylcholine (DLPC) at the air/water interface was investigated by the Langmuir film balance. Surface pressure-area isotherms suggest that mixtures containing 25.0-62.5-mol% DLPC (range of composition investigated) are phase-s...

The title compound, {[Ag(C15H16S2)2]SbF6·0.5C4H10O}n, was obtained from the self-assembly of AgSbF6 and 1,3-bis(phenylsulfanyl)propane. Each AgI ion is coordinated by four S atoms from different ligands, forming a distorted tethrahedral geometry. Each ligand links adjacent AgI ions, forming an extended two-dimensional grid-like framework. SbF6− ion...

The title compound, {[Ag(C15H16S2)2]SbF6·0.5C4H10O}n, was obtained from the self-assembly of AgSbF6 and 1,3-bis­(phenyl­sulfan­yl)propane. Each AgI ion is coordinated by four S atoms from different ligands, forming a distorted tethrahedral geometry. Each ligand links adjacent AgI ions, forming an extended two-dimensional grid-like framework. SbF6⁻...

Films of hyaluronan (HA) and a phosphorylcholine-modified chitosan (PC-CH) were constructed by the polyelectrolyte multilayer (PEM) deposition technique and their buildup in 0.15 M NaCl was followed by atomic force microscopy, surface plasmon resonance spectroscopy (SPR), and dissipative quartz crystal microbalance (QCM). The HA/PC-CH films were st...

The redox-induced assembly of amphiphilic molecules and macromolecules at electrode surfaces is a potentially attractive means of electrochemically modulating the organization of materials and nanostructures on solid substrates via ion-pairing interactions or charge-transfer complexation. In this regard, we have investigated the potential-induced a...

Two topologically comparable complexes, [Ag6(CF3CO2)3(L1-Me)3(SCH3)3]infinity (1) and [Ag6(CF3CF2CO2)3(L1-Me)2(SCH3)3(H2O)]infinity (2), were prepared and characterized by single-crystal diffractometry. The structures consist of Ag12S6 clusters linked by bis(methylthio)methane ligands, L1-Me, thus forming 1D coordination polymers. The 12 Ag atoms o...

A series of coordination networks has been synthesized by the self-assembly of the small bis(methylthio)methane building block and AgX (X ) NO3 - (1), ClO4 - (2, 3), p-TsO- (4), CF3COO- (5), CF3CF2CF2COO- (6), CF3SO3 - (7), C6H5COO- (8), CH3SO3 - (9), and HOOCCF2CF2COO- (10)) in order to rationalize the effect of the size of the anions and the liga...

The stability of polyelectrolyte multilayer assemblies was investigated with emphasis on the effects of solution ionic strength, pH, and polymer molecular weight on the film thickness and surface topography. The multilayers consisting of two polysaccharides, the polyanion sodium hyaluronate (HA) and the polycation chitosan (CH) were studied using s...

In the title structure, C24H32N2O2, the mol­ecule lies on a crystallographic inversion centre at the mid-point of the central C—C bond. The planar OCN—(CH2)n—NCO segment is in an all-trans configuration. The NH group of the amide group is involved in a single hydrogen bond to the O atom of a symmetry-related mol­ecule to form one-dimensional ribbon...

This report describes the synthesis and X-ray characterization of a series of L(n)AgX complexes wherein Ln = PhS(CH2)nSPh (n = 2, 4, 6, 10) and X = CF3SO3-, CF3COO-, CF3CF2COO-, CF3CF2CF2COO-, NO3-, and ClO4-. This study was undertaken in order to rationalize the structure of the coordination networks formed as a function of the anion coordinating...

The synthesis and characterization of nine coordination networks based on 1,3-bis(phenylthio)propane, L(3), and silver(I) salts of PF(6)(-) (1), CF(3)COO(-) (2), CF(3)CF(2)COO(-) (3), CF(3)CF(2)CF(2)COO(-) (4), p-TsO(-) (5, 6), and CF(3)SO(3)(-) (7-9) are reported. Only 1 and other "isostructural" complexes with weakly coordinating anions such as C...

The title compound, trans-[PdCl2(PhSCH2SPh)2], crystallizes with two half-mol­ecules in the asymmetric unit and each independent mol­ecule lies about a crystallographic inversion center. In each mol­ecule, one S atom of the bis­(phenyl­sulfan­yl)methane ligand is coordinated to the Pd atom while the second S atom of the same ligand is uncoordinated...

The title compound, C16H18S2 (or L 6), crystallizes with two half-molecules in the asymmetric unit and each independent molecule lies about a crystallographic center of symmetry. The aliphatic segment of this ligand is in an all-trans conformation. © 2005 International Union of Crystallography Printed in Great Britain - all rights reserved.

The title compound, trans-[PdCl2(PhSCH2SPh)2], crystallizes with two half-mol­ecules in the asymmetric unit and each independent mol­ecule lies about a crystallographic inversion center. In each mol­ecule, one S atom of the bis­(phenyl­sulfan­yl)methane ligand is coordinated to the Pd atom while the second S atom of the same ligand is uncoordinated...

The title compound, C16H18S2 (or L⁶), crystallizes with two half-mol­ecules in the asymmetric unit and each independent mol­ecule lies about a crystallographic center of symmetry. The aliphatic segment of this ligand is in an all-trans conformation.

In the title crystal structure, C14H14S2, L², the mol­ecules lie on crystallographic inversion centers. The phen­yl rings are nearly perpendicular to the planar S—C—C—S group of atoms.

In the title structure, C22H30S2, L¹⁰, the asymmetric unit contains two independent mol­ecules, both of which lie on crystallographic inversion centers, and the aliphatic chains are in the all-trans conformation. The crystal structure is stabilized by a combination of van der Waals forces and weak C—H⋯π(arene) inter­actions.

The layer-by-layer growth of multilayer assemblies of two polysaccharides, the polyanion hyaluronan (HA) and the polycation chitosan (CH), was investigated using atomic force microscopy (AFM) and surface plasmon resonance (SPR) spectroscopy, with primary emphasis on the effect of the polysaccharide molecular weights on the film thickness and surfac...

A number of complexes were synthesized to rationalize the structures of Ag(I) complexes with a small flexible bidentate ligand, bis(phenylthio)methane, when the anion is varied. We compared two similar “spherical” anions, ClO4 - (1) and BF4 - (2), as well as two slightly “elongated” ones, CF3COO- (3) and CF3SO3 - (4, 5). Complexes with a longer ani...

The stereoselective phospholipase A2-catalyzed hydrolysis of patterned phospholipid bilayers consisting of the l- and d-isomers of alpha-dilauroylphosphatidylcholine (DLPC) and alpha-dipalmitoylphosphatidylcholine (DPPC) is reported. The stereochemically directed enzyme lithography demonstrated herein allows the parallel modification of large surfa...

Langmuir films of gold nanoparticles derivatized with acid-terminated alkylthiol chains were analyzed at room temperature. The microscopic structures of the films were probed as a function of area/particle by using various surface-sensitive x-ray techniques. The isotherms of the gold films exhibited a coexistence plateau that was consistent with a...

A microcantilever-based system capable of measuring surface stress changes in thin films which occur during electrochemical reactions is presented. In this system, the microcantilever provides both physical support and electrical contact to the thin film deposited on the metal coated face of the lever. The microcantilever serves as the working elec...

Interfacial stress changes at electroactive self-assembled monolayers have been investigated by monitoring the potential-induced deflection of Au-coated microcantilevers modified with 12-ferrocenyl-1-dodecanethiol in aqueous perchloric acid solution. Oxidation of the surface-bound ferrocene generates a compressive surface stress which results in th...

Atomic force microscopy imaging of dipalmitoylphosphatidylcholine (DPPC)/dilauroylphosphatidylcholine (DLPC) monolayers deposited onto alkanethiol modified-gold surfaces by the Langmuir–Schaefer technique was used to investigate domain formation in a binary system where phase separation arises from a difference in the alkyl chain lengths of the lip...

A new methodology has been developed to create an extensive pattern of parallel stripes, 150−250 nm wide, in phospholipid bilayers supported on mica. These striped bilayers are prepared by the Langmuir−Blodgett (LB) film technique. A striped monolayer consisting of two phospholipids in different states (condensed and liquid-expanded) is used to dir...

Selective adsorption of human serum albumin and human γ globulin to the liquidlike phase of chemically homogeneous, mixed phospholipid monolayers supported on a solid surface gives rise to arrays of linear 150-200-nm-wide grooves (see images). The protein-covered areas could be metallized by the adsorption of Au nanoparticles.

Atomic force microscopy (AFM) has been used to investigate the morphology of mixed monolayers of 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) deposited onto mica by the Langmuir−Blodgett technique. At compositions near the critical point where phase separation is first observed by AFM, this...

A new methodology has been used to create an extensive array of nanometer-sized features. The Ar+ milling of Si/SiOx and gold surfaces covered with a diblock copolymer mask with an intrinsic topological nanopattern yields transfer of the nanopattern. Mask removal was tracked using XPS, and the final arrays were characterized by AFM and LFM. Frictio...

The dynamics of the alkyl chains below and above the chain-melting transition temperature of long-chain silver n-alkanethiolate layered compounds were studied using variable-temperature 2H NMR and IR spectroscopies. Two specifically deuterated compounds, silver-d35-octadecanethiolate [AgSCH2(CD2)16CD3] and silver-1,1-d2-octadecanethiolate [AgSCD2(C...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The thermal behavior of a self-assembled silver alkanethiolate layered material (AgSCn, n = 12) has been explored using two spectroscopic techniques:  13C CPMAS NMR (13C cross-polarization magic angle spinning NMR) and FTIR (Fourier transform infrared) spectroscopy. The goal was to correlate structural changes monitored by spectroscopy with the pha...

In this Account, we discuss the dynamic features of self-assembled monolayers (SAMs) on both planar and nonplanar substrates. Our focus is on organothiol and organic acid-based monolayers. Results from variable-temperature electrochemical, calorimetric, vibrational, and solid-state NMR spectroscopic measurements lead to a convergent description of...

Although self-assembled monolayers (SAMs) of alkylthiols on planar gold (2D SAMs) and on gold nanoparticles (3D SAMs) have been intensely studied, the actual nature of the Au−S bonding remains poorly characterized. Comparison of the X-ray photoelectron spectroscopy (XPS) spectra of 2D and 3D SAMs and “reference” Au(I) complexes, sometimes referred...

We describe a series of interfacial biomolecular architectures employed for studies aimed at elucidating the structural and dynamical factors governing biorecognition and binding reactions between surface-attached biotin-derivatives and analogues and streptavidin from solution. We compare binding matrices based on mixed lipid monolayers transferred...

Communication: An approach to the immobilization of compounds on sur- faces that should also be applicable to combinatorial libraries is described. The attachment of an electrochemically polymerizable phenol group to molecules, in this case biotin, followed by anodic polymerization is shown to yield thin insulating layers. When the polymerization t...

The combination of surface plasmon spectroscopy (SPS) and atomic force microscopy (AFM) with electrochemical methods (cyclic voltammetry, potential step) is used to (i) probe the film/substrate interaction in alkanethiol monolayers formed on gold surfaces and (ii) monitor the electrochemically driven deposition of organic molecules onto a metal sur...

In the present work, we have used reflection-absorption infrared spectroscopy (RAIRS) to investigate the temperature behavior of n-alkanethiols adsorbed on gold substrates. A careful examination of the spectra (frequencies, integrated intensities, and line widths) reveals at least two different types of thermally induced disorder as the temperature...

Self-assembled monolayers (SAMs) with terminal hydrogen bonding groups can have remarkably different structure and dynamics to those of the more familiar alkenethiol SAMs. The effect of carboxylic acid terminal groups on the structure and dynamics of gold nanoparticle SAMs is investigated by C-13 NMR, 2D WISE NMR, and FTIR spectroscopies. A markedl...

Gold nanoparticles, ca. 30 Å in diameter, have been derivatized with specifically deuterated (position 1 and positions 10 to 13) and perdeuterated (positions 2 to 18) octadecanethiols (C18SH). The phase behavior of the octadecanethiolate monolayers chemisorbed onto the colloidal gold surface was characterized by differential scanning calorimetry (D...

The structure and dynamical behavior of short and long chain alkanethiols, CH3(CH2)7SH and CH3(CH)17SH, and of a hydroxyalkanethiol, HO(CH2)16SH, adsorbed onto gold nanoparticles were studied by variable temperature solid-state 13C NMR spectroscopy. In both the solution and solid state, the resonances of the first three carbons next to the sulfur h...

Self-assembled monolayers (SAMs) of n-alkanethiolates on gold, silver, and copper have been intensively studied both as model organic surfaces and as modulators of metal surface properties. Sensitivity restrictions imposed by monolayer coverage and the low surface area of planar metal substrates, however, limit the characterization of these films i...

Reflection‐absorption infrared spectroscopy at near grazing incidence is used to investigate the thermal stability of self‐assembled monolayers of alkyl thiols, HS–(CH 2 ) n-1 ‐R, adsorbed on polycrystalline metal surfaces. The spectral features of the C–H stretching region have been carefully analyzed in the temperature range from 150 to 450 K. Th...

Ordnungs/Unordnungs-Übergänge in Alkanthiol-Monoschichten (schematische Darstellung unten) konnten nun durch temperaturabhängige Messung des Reduktionsstromes eines Redoxpaares an einer unter geeigneten Bedingungen mit Alkanthiolen modifizierten Au-Elektrode nachgewiesen werden. Der Elektronentransfer ist dabei offenbar nicht auf einen Tunnelprozeß...

Glucose oxidase (GOx) was covalently modified at pH 7.2 with ferrocenecarboxylic acid (FCA), ferrocenedicarboxylic acid (FDA), and ferroceneacetic acid (FAA) using 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide hydrochloride (EDC) and N-hydroxysulfosuccinimide to promote selective coupling to surface lysines. Reagent ratios were varied to obtain d...

Trichloroacetic acid (TCA; 5%) was found to release iron quantitatively from a number of ferrocene derivatives. Free iron was then determined spectrophotometrically, using 564 nm absorbance maximum of the Fe(ferrozine)2+3 complex [ferrozine = 3-(2-pyridyl)-5,6-bis(4-phenylsulfonic acid)-1,2,4-triazine]. As TCA also deproteinizes solutions, the ferr...