In Situ Photocatalytically Heterostructured ZnOAg Nanoparticle Composites as Effective Cathode‐Modifying Layers for Air‐Processed Polymer Solar Cells

A heterostructured semiconductor–metal ZnO?Ag nanoparticle (NP) composite was constructed through a straightforward photocatalytic strategy by using UV irradiation of ZnO NPs and an aqueous solution of Ag precursor. The ZnO?Ag NP composites serve as an effective cathode‐modifying layer in polymer solar cells (PSCs) with increased short‐circuit current density owing to the light‐trapping effect, and improved optical and electrical conductivity properties compared with pure ZnO NPs. The Ag NPs, which are photodeposited in situ on ZnO NPs, can act as effective antennas for incident light to maximize light harvesting and minimize radiative decay or nonradiative losses, consequently resulting in the enhanced photogeneration of excitons in PSCs. Systematic photoelectron and ‐physical investigations confirm that heterostructured ZnO?Ag NPs can significantly improve charge separation, transport, and collection, as well as lower charge recombination at the cathode interface, leading to a 14.0 % improvement in air‐processed device power conversion efficiency. In addition, this processable, cost‐effective, and scalable approach is compatible with roll‐to‐roll manufacturing of large‐scale PSCs.     

High‐Level Incorporation of Silver in Gold Nanoclusters: Fluorescence Redshift upon Interaction with Hydrogen Peroxide and Fluorescence Enhancement with Herbicide

High‐level incorporation of Ag in Au nanoclusters (NCs) is conveniently achieved by controlling the concentration of Ag⁺ in the synthesis of bovine serum albumin (BSA)‐protected Au NCs, and the resulting structure is determined to be bimetallic Ag₂₈Au₁₀‐BSA NCs through a series of characterizations including energy‐dispersive X‐ray spectroscopy, mass spectroscopy, and X‐ray photoelectron spectroscopy, together with density functional theory simulations. Interestingly, the Ag₂₈Au₁₀ NCs exhibit a significant fluorescence redshift rather than quenching upon interaction with hydrogen peroxide, providing a new approach to the detection of hydrogen peroxide through direct comparison of their fluorescence peaks. Furthermore, the Ag₂₈Au₁₀ NCs are also used for the sensitive and selective detection of herbicide through fluorescence enhancement. The detection limit for herbicide (0.1 nm ) is far below the health value established by the U.S. Environmental Protection Agency; such sensitive detection was not achieved by using AuAg NCs with low‐level incorporation of Ag or by using the individual metal NCs.     

The importance of protonation and tautomerization in relative binding affinity prediction: a comparison of AMBER TI and Schrödinger FEP

In drug discovery, protonation states and tautomerization are easily overlooked. Through a Merck–Rutgers collaboration, this paper re-examined the initial settings and preparations for the Thermodynamic Integration (TI) calculation in AMBER Free-Energy Workflows, demonstrating the value of careful consideration of ligand protonation and tautomer state. Finally, promising results comparing AMBER TI and Schrödinger FEP+ are shown that should encourage others to explore the value of TI in routine Structure-based Drug Design.     

LC‐MS/MS analysis of Gegen Qinlian Decoction and its pharmacokinetics after oral administration to rats

A liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) method was developed and validated for the simultaneous determination of 12 constituents of Gegen Qinlian Decoction (GQD), namely puerarin, daidzein, baicalin, wogonoside, wogonin, liquiritin, liquiritigenin, berberine, jatrorrhizine, palmatine, coptisine and glycyrrhetic acid, in rat plasma. The plasma samples were spiked with the internal standard (IS) carbamazepine acidified with HCl and extracted by liquid–liquid extraction with ethyl acetate. Chromatographic separation was achieved on a Shiseido Capcell PAK C₁₈ column utilizing a gradient elution profile and a mobile phase consisting of (A) 0.1% formic acid in water and (B) acetonitrile. Detection was performed in the multiple reaction monitoring mode using electrospray ionization in the positive ion mode at a flow rate of 0.3 mL/min and a run time of 8 min. All of the calibration curves gave good linearity (r > 0.9930) over the concentration range from 0.6–360 to 16.2–9720 ng/mL for all components. The intra‐ and inter‐day precisions were <15.0% in terms of the relative standard deviation, and the accuracies were within ±13.7% in terms of the relative error. The method was successfully applied to investigate the pharmacokinetics of the major active compounds of Gegen Qinlian Decoction after its oral administration to rats. Copyright © 2014 John Wiley & Sons, Ltd.