At-line bioprocess monitoring by immunoassay with rotationally controlled serial siphoning and integrated supercritical angle fluorescence optics

In this paper we report a centrifugal microfluidic “lab-on-a-disc” system for at-line monitoring of human immunoglobulin G (hIgG) in a typical bioprocess environment. The novelty of this device is the combination of a heterogeneous sandwich immunoassay on a serial siphon-enabled microfluidic disc with automated sequential reagent delivery and surface-confined supercritical angle fluorescence (SAF)-based detection. The device, which is compact, easy-to-use and inexpensive, enables rapid detection of hIgG from a bioprocess sample. This was achieved with, an injection moulded SAF lens that was functionalized with aminopropyltriethoxysilane (APTES) using plasma enhanced chemical vapour deposition (PECVD) for the immobilization of protein A, and a hybrid integration with a microfluidic disc substrate. Advanced flow control, including the time-sequenced release of on-board liquid reagents, was implemented by serial siphoning with ancillary capillary stops. The concentration of surfactant in each assay reagent was optimized to ensure proper functioning of the siphon-based flow control. The entire automated microfluidic assay process is completed in less than 30 min. The developed prototype system was used to accurately measure industrial bioprocess samples that contained 10 mg mL⁻¹ of hIgG.     

Direct Evidence for Intermolecular Oxidative Addition of σ(SiSi) Bonds to Gold

Oxidative addition plays a major role in transition‐metal catalysis, but this elementary step remains very elusive in gold chemistry. It is now revealed that in the presence of GaCl₃, phosphine gold chlorides promote the oxidative addition of disilanes at low temperature. The ensuing bis(silyl) gold(III) complexes were characterized by quantitative ³¹P and ²⁹Si NMR spectroscopy. Their structures (distorted Y shape) and the reaction profile of σ(Si? Si) bond activation were analyzed by DFT calculations. These results provide evidence for the intermolecular oxidative addition of σ(Si? Si) bonds to gold and open promising perspectives for the development of new gold‐catalyzed redox transformations.     

Structurally Tunable 3‐Cyanoformazanate Boron Difluoride Dyes

The straightforward synthesis of a series of 3‐cyanoformazanate boron difluoride dyes is reported. Phenyl, 4‐methoxyphenyl and 4‐cyanophenyl N‐substituted derivatives were isolated and characterized by single‐crystal X‐ray crystallography, cyclic voltammetry, and UV/Vis spectroscopy. The compounds were demonstrated to possess tunable, substituent‐dependent absorption, emission, and electrochemical properties, which were rationalized through electronic structure calculations.     

Synthesis of Highly Functionalized Diaryl Ethers by Copper‐Mediated O‐Arylation of Phenols using Trivalent Arylbismuth Reagents

Highly functionalized diaryl ethers were prepared by copper(II) acetate mediated O‐arylation reaction of phenols using trivalent organobismuthanes. The reaction is performed under simple conditions and tolerates a wide diversity of functional groups on the phenol and on the organobismuth reagent. Substoichiometric amounts of catalyst can be used by performing the reaction under an oxygen atmosphere. The N‐arylation of pyridones is also reported.     

Deep-Eutectic-Solvent-Based Self-Healing Polymer Electrolyte for Safe and Long-Life Lithium-Metal Batteries

The deployment of high-energy-density lithium-metal batteries has been greatly impeded by Li dendrite growth and safety concerns originating from flammable liquid electrolytes. Herein, we report a stable quasi-solid-state Li metal battery with a deep eutectic solvent (DES)-based self-healing polymer (DSP) electrolyte. This electrolyte was fabricated in a facile manner by in situ copolymerization of 2-(3-(6-methyl-4-oxo-1,4-dihydropyrimidin-2-yl)ureido)ethyl methacrylate (UPyMA) and pentaerythritol tetraacrylate (PETEA) monomers in a DES-based electrolyte containing fluoroethylene carbonate (FEC) as an additive. The well-designed DSP electrolyte simultaneously possesses non-flammability, high ionic conductivity and electrochemical stability, and dendrite-free Li plating. When applied in Li metal batteries with a LiMn₂O₄ cathode, the DSP electrolyte effectively suppressed manganese dissolution from the cathode and enabled high-capacity and a long lifespan at room and elevated temperatures.     

Kristallstrukturbestimmung von N-Trimethylsily-N′-methylimidazoliumbromid

Crystal Structure Determination of N-Trimethylsilyl-N′-Methylimidazolium Bromide The reaction of Trimethylbromosilane and N-Methylimidazole (NMI) led to a 1:1 compound stable at room temperature. The reaction was carried out at room temperature and colorless single crystals were obtained by sublimation. The addition compound crystallizes in the orthorhombic space group Pbnb (No. 56) with lattice constants a = 1218.3(2)pm, b = 1333.6(1)pm, c = 1360.2(2)pm, Z = 8, D_calc = 1.414 g/cm³. For 1506 independent reflections, measured at 21°C the structure could be refined to R = 0.067 and R_w = 0.062.     

Weak localization and electron-electron interactions in thin Pd and PdHx films

We investigate the temperature and magnetic field dependence of the resistance R of thin Pd and PdHx films. We show that the logarithmic behaviour R(T) ≈ A ln T is dominated in Pd by the interaction effect. Loading progressively with hydrogen shows first no change in A and then a decrease followed by a sign reversal when superconducting fluctuations prevail. The application of a magnetic field restores then a positive and large value of A. These data are analyzed within recent theories.