Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
The following papers are very important in the opinion of two referees. They will be published as soon as possible.
Two-Color RESOLFT Nanoscopy with Green and Red Fluorescent Photochromic Proteins
Flavie Lavoie-Cardinal, Nickels A. Jensen, Volker Westphal, Andre C. Stiel, Andriy Chmyrov, Jakob Bierwagen, Ilaria Testa, Stefan Jakobs,* Stefan W. Hell*
Dual-color live-cell RESOLFT superresolution microscopy is demonstrated with green- and red-emitting switchable fluorescent protein tags. The red-emitting tag is a novel reversibly switchable protein, rsCherryRev1.4, enabling a resolution up to four times over the diffraction barrier. Dual-color RESOLFT works with both single and multiple ‘donuts’ using more than 23000 ‘donuts’ in parallel.
Received November 04, 2013, published online January 21, 2014, DOI: 10.1002/cphc.201301016 – read now.
On the Electrochemical Deposition and Dissolution of Divalent Metal Ions
Wolfgang Schmickler,* Leandro M. C. Pinto, Paola Quaino, Elizabeth Santos
Divalent metal ions like Cu++ and Zn++ have strong solvation shells and cannot be deposited directly. They first undergo an outer-sphere electron transfer to the monovalent ions, which fit well into the water structure and can be deposited. In the case of copper, the energy of Cu+ is only a little higher than that of Cu++, and this path is favorable. In contrast, the energy of Zn+ is too high to be a favorable intermediate. In accord with experimental data, the authors suggest that zinc deposition is catalyzed by anions.
Received September 15, 2013, published online December 02, 2013, DOI: 10.1002/cphc.201300856 – read now.
O-H···N and C-H···O Hydrogen Bonds Control Hydration of Pivotal Tropane alkaloids: Tropinone···H2O Complex
Patricia Écija, Montserrat Vallejo-López, Luca Evangelisti, José A. Fernández, Alberto Lesarri, Walther Caminati, Emilio J. Cocinero*
The effect of monohydration in the equatorial/axial isomerism of the common motif of tropane alkaloids has been investigated in a supersonic expansion by using Fourier-transform microwave spectroscopy. The rotational spectrum reveals that the equatorial isomer is the dominant species in tropinone···H2O. We show how water interacts with tropinone, forming a hydrogen bond with the amino group rather than with the carboxylic group.
Received December 22, 2013, published online February 24, 2014, DOI: 10.1002/cphc.201301213 – read now.
From Molecular Structure to Spectroscopic and Material Properties: Computational Investigation of a Bent-Core Nematic Liquid Crystal
Alberta Ferrarini, Cristina Greco, Elisa Frezza, Alberto Marini
Bent-core liquid crystals have a number of unconventional properties that remain the object of debate. By means of an integrated theoretical and computational methodology, Ferrarini and colleagues are able to bridge the molecular structure to the materials' properties. The authors simultaneously predict 13C-NMR chemical shifts, which are defined with atomistic resolution, and elastic constants that control deformations on the macroscopic scale. By a proper account of the molecular geometry, the researchers show that the unusual bend elasticity of these systems subtly depends on their bent shape.
Received November 06, 2013, published online January 27, 2014, DOI: 10.1002/cphc.201301030 – read now.
Non-Uniform Helix Unwinding of Cholesteric Liquid Crystals in Cells with Interdigitated Electrodes
Mariacristina Rumi, Vincent P. Tondiglia, Lalgudi V. Natarajan, Timothy J. White, Timothy J. Bunning
In liquid crystal cells with interdigitated electrodes, the electro-optic response of cholesteric materials to an electric field applied perpendicular to the helical axis is found to depend on the geometrical parameters of the cells. In particular, in cells with narrow gaps between electrodes, the unwinding of the cholesteric helix in response to an electric field occurs in a non-uniform manner through the thickness of the cell, due to a large field gradient. This heterogeneity leads to different pitches and selective Bragg reflection wavelengths on the cell side with the patterned electrodes compared to the opposite cell side.
Received October 28, 2013, published online January 02, 2014, DOI: 10.1002/cphc.201300995 – read now.
Reorientational Dynamics of Water Confined in Zeolites
Damien Laage, Aoife C. Fogarty, François-Xavier Coudert, Anne Boutin
Situations in which water is strongly confined are of great importance in many contexts, ranging from biochemistry to chemical engineering, and such a confinement is known to affect the properties of water. The authors combine numerical simulations and analytic modeling to analyze the impact of an extreme hydrophobic confinement, such as that found in some zeolites, on water dynamics. Their results suggest that the main perturbation is due to the presence of the interface –and to its chemical nature– and to a lesser extent to confinement.
Received October 09, 2013, published online January 21, 2014, DOI: 10.1002/cphc.201300928 – read now.
Phthalocyanine-Based Organometallic Nanocages: Properties and Hydrogen Storage
Guizhi Zhu, Yawei Li, Kun Lü, and Qiang Sun*
Tremendous attention has been paid to phthalocyanine (Pc)-based 1D nanotubes and 2D nanosheets. However, until now, no study has been reported for Pc-based 0D nanocages. We present first-principles calculations with Grand Canonical Monte Carlo (GCMC) simulations for the geometries, stabilities, electronic structures, optical properties, and hydrogen-storage capabilities of Pc-based nanocages. This study provides new insights into Pc-based nanostructures and their potential applications..
Received September 07, 2013, published online November 29, 2013, DOI: 10.1002/cphc.201300830 – read now.
The Role of Molecular Dipole Orientation in Single-Molecule Fluorescence Microscopy and Implications for Super-Resolution Imaging
Mikael P. Backlund, Matthew D. Lew, Adam S. Backer, Steffen J. Sahl, and W. E. Moerner*
We review methods for determining the orientation of single molecules from fluorescence microscopy images. We focus, in particular, on those which rely on the spatial variation of the emission and are compatible with wide-field imaging. The limits that molecular transition dipole orientation impose on the accuracy and resolution of single-molecule-based super-resolution microscopy are discussed. By using both the quadrated pupil and double-helix point-spread function imaging modalities, we address the rotational mobility of fluorescent labels in a biological sample, namely microtubules immunolabeled with AlexaFluor 647.
Received September 24, 2013, published online December 30, 2013, DOI: 10.1002/cphc.201300880 – read now.
Increasing the Brightness of Cyanine Fluorophores for Single-molecule and Super-resolution Imaging
Kathrin Klehs, Christoph Spahn, Ulrike Endesfelder, Steven F. Lee, Alexandre Fürstenberg, Mike Heilemann
The brightness of fluorescent dyes is a key parameter in single-molecule localization microscopy because it eventually dictates the resolution of such experiments. The paper by Klehs et al. demonstrates that the brightness of red-emitting cyanine dyes, which are widely used in super-resolution imaging, can be enhanced up to 2.5 times by performing experiments in heavy water (D2O) instead of water (H2O), leading to a corresponding increase in localization precision at virtually no cost.
Received September 23, 2013, published online December 02, 2013, DOI: 10.1002/cphc.201300874 – read now.
Study of the Diradicaloid Character in a Prototypical Pancake Bonded Dimer: The Stacked Tetracyanoethylene (TCNE) Anion Dimer and the Neutral K2TCNE2 Complex
Zhong-hua Cui, Hans Lischka,* Thomas Mueller, Felix Plasser, Miklos Kertesz*
Unusual carbon-carbon contact distances occur in dimers and aggregates of radicals that are significantly shorter than van der Waals contacts and much longer than extremely stretched σ-bonds. These "pancake bonds" display special features of chemical bonding: strong diradicaloid character, some covalent multicenter character, and significant contributions from dispersion interactions and Pauli repulsion. In the present high-level theoretical analysis the authors applied the multi-reference averaged quadratic coupled-cluster (MR-AQCC) method to a prototypical pancake bonded system: the tetracyanoethylene (TCNE) anion dimer. By separating the global Coulomb and van der Waals contributions (dispersion plus Pauli repulsion), Cui et al. conclude that the crucial part of the interaction energy in this pancake bonded system is almost exclusively due to the correlated electron pair, which is delocalized over both radical centers and possesses significant diradicaloid character.
Received August 26, 2013, published online November 20, 2013, DOI: 10.1002/cphc.201300784 – read now.
Rolling up a Graphene Sheet
Matteo Calvaresi, M. Quintana, P. Rudolf, F. Zerbetto, M. Prato
Graphene is the mother of all graphitic forms, and carbon nanotubes are nothing but rolled up graphene layers. Sealing a nanotube is challenging, but ultrasonication, together with the judicious use of a reducing agent that partly inhibits reactions promoted by reactive oxygen species, does it!
Received April 04, 2013, published online June 11, 2013, DOI: 10.1002/cphc.201300337 – read now.
Angle-Resolved Strong-Field Ionization of Polyatomic Molecules: More than the Orbitals Matters
Oumarou Njoya, Spiridoula Matsika and Thomas Weinacht
Strong-field ionization plays a critical role in attosecond pulse generation and molecular imaging. It has been shown to be sensitive to the shape of molecular orbitals, and can therefore be used as a tool for studying time-dependent changes to molecular structure. Using a pump-probe scheme to initiate and capture excited-state dynamics, the authors discuss three molecules whose orbital structures are the same but whose angle and time-dependent yields differ significantly. This suggests that the angle dependence of strong-field molecular ionization is sensitive to more than the shape of the molecular orbital from which an electron is removed.
Received December 14, 2012, published online March 20, 2013, DOI: 10.1002/cphc.201201045 – read now.
A Chemical Lift-Off Process: Removing Non-Specific Adsorption in an Electrochemical Epstein-Barr Virus Immunoassay
Lutz Stratmann, Magdalena Gebala, Wolfgang Schuhmann*
The detection limits of immunoassays and biosensors are often limited by the non-specific adsorption of proteins in complex samples. By forming a self-assembled monolayer, which can be locally chemically activated using scanning electrochemical microscopy, an Epstein-Barr virus immunoassay with amplified electrochemical readout was developed. The monolayer additionally comprises a sacrificial layer which can be removed by acid hydrolysis leading to a chemical lift-off of non-specifically adsorbed species in analogy to the lift-off techniques in photolithography.
Received January 11, 2013, published online May 16, 2013, DOI: 10.1002/cphc.201300029 – read now.
Optimization of a Membraneless Glucose/Oxygen Enzymatic Biofuel Cell Based on a Bioanode with High Coulombic Efficiency and Current Density
Lo Gorton*, Minling Shao, Muhammad Nadeem Zafar, Magnus Falk, Roland Ludwig, Christoph Sygmund, Clemens K. Peterbauer, Dmitrii A. Guschin, Dónal Leech, Sergey Shleev, Wolfgang Schuhmann
The columbic efficiency of enzymatic bioanodes is very important. Bioanodes based on one glucose redox enzyme have low efficiency, extracting only two electrons per glucose. In contrast, biocathodes based on multicopper oxidases are 100% efficient, since they reduce O2 directly to H2O. For ex vivo biodevices (on a tooth, on skin, or on a contact lens), complete oxidation of glucose is crucial. Saliva and tears contain a very low glucose concentration (approx. 0.1 mM) compared to 5 mM in blood. Also, the amount of glucose is limited in the low volume of saliva, sweat or tears. In tears, it is about 10 μL with a flow rate of about 1 μL per min. Thus, the total amount of glucose in tears is only 10-9 M with an addition of 10-10 M per min. Complete bioelectrooxidation of glucose by biofuel cells is obviously needed to design useful biodevices.
Received January 15, 2013, published online April 08, 2013, DOI: 10.1002/cphc.201300046 – read now.
Electrochemically Actuated Stop-Go Valves for Capillary Force-Operated Diagnostic Microsystems
Ioanis Katakis, Alemayehu P. Washe, Pablo Lozano Sanchez, and Diego Bejarano-Nosas
Microchannels containing sequential detection sites for the quantification of analytes and the quality control of reagents are the simplest immunosensing devices if they incorporate a flow control for reagent dissolution and incubation. This can be achieved by printing pairs of superhydrophobic electrodes transversal to the capillary flow direction. Low potentials activate the flow allowing stop/go steps. Since the structural elements, the flow-control device, and the sensors can all be produced by screen printing, and all the operations can be actuated by a portable potentiostat, this work could be an important step towards the development of quantitative, low-cost, easy-to-use diagnostic devices.
Received January 15, 2013, published online April 16, 2013, DOI: 10.1002/cphc.201300042 – read now.
Integrated Devices to Simultaneously Realize Energy Conversion and Storage
H.S. Peng, Tao Chen, and Zhibin Yang
Other forms of energy are generally converted into electric energy and then stored in electrochemical devices through external electric wires. Peng and colleagues describe novel integrated energy devices that simultaneously realize energy conversion and storage. Both planar and wire architectures are carefully illustrated with an emphasis on the “energy wire”. The wire structure enables unique and promising applications; for example, such wires can be woven into clothes or other complex flexible equipments by using a conventional textile technology.
Received January 13, 2013, published online April 05, 2013, DOI: 10.1002/cphc.201300032 – read now.