Synthesis of Fluorescent Gold Nanoclusters Directed by Bovine Serum Albumin and Application for Nitrite Detection

In the present work, gold nanocluster (GNC) induced by bovine serum albumin (BSA) was synthesized as a novel fluorescence probe to detect nitrite (NO₂ ^?) sensitively and selectively. The fluorescence of GNC was found to be quenched effectively by NO₂ ^?. Under the optimum conditions, it was found that the change of fluorescence intensity was proportional with the concentration of NO₂ ^? in the linear range of 0.1–50 μM (R?=?0.9990), with a detection limit (S/N?=?3) of 30 nM. The absorption spectroscopy, circular dichroism (CD), and X-ray photoelectron spectroscopy (XPS) studies were employed to discuss the quenching mechanism. In addition, the present approach was successfully applied in real water samples.     

Benzodifuran‐containing well‐defined π‐conjugated polymers for photovoltaic cells

Two well‐defined alternating π‐conjugated polymers containing a soluble electroactive benzo[1,2‐b:4,5‐b′]difuran (BDF) chromophore, poly(BDF‐(9‐phenylcarbazole)) (PBDFC), and poly(BDF‐benzothiadiazole) (PBDFBTD) were synthesized via Sonogashira copolymerizations. Their optical, electrochemical, and field‐effect charge transport properties were characterized and compared with those of the corresponding homopolymer PBDF and random copolymers of the same overall composition. All these polymers cover broad optical absorption ranges from 250 to 750 nm with narrow optical band gaps of 1.78–2.35 eV. Both PBDF and PBDFBTD show ambipolar redox properties with HOMO levels of ?5.38 and ?5.09 eV, respectively. The field‐effect mobility of holes varies from 2.9 × 10^?8 cm² V^?1 s^?1 in PBDF to 1.0 × 10^?5 cm² V^?1 s^?1 in PBDFBTD. Bulk heterojunction solar cell devices were fabricated using the polymers as the electron donor and [6,6]‐phenyl‐C₆₁‐butyric acid methyl ester as the electron acceptor, leading to power conversion efficiencies of 0.24–0.57% under air mass 1.5 illumination (100 mW cm^?2). These results indicate that their band gaps, molecular electronic energy levels, charge mobilities, and molecular weights are readily tuned by copolymerizing the BDF core with different π‐conjugated units. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Thermogravimetric analysis of carbide slag

Potential of carbide slag as transesterification catalyst is validated. Combined with X-ray fluorescence for ingredient determination, X-ray diffraction for textural phase analysis, scanning electron microscope for surface morphology observation and Hammett indicator for basic strength mensuration, thermal event of carbide slag is investigated through thermogravimetric analysis to estimate the potential of this calcium-based industrial waste as transesterification catalyst. Further, kinetic parameters are calculated through model-free method, where the experiments are conducted at temperature heating rates of 5, 10, 15, and 20 K min^?1. As for activation energy and reaction order, Vyazovkin method and Avrami theory are respectively mentioned. Meanwhile, catalytic performance of carbide slag is labeled by transesterification efficiency and calcium hydroxide is conditionally mentioned for comparison. In conclusion, potential of carbide slag as transesterification catalyst is adequately validated.     

Vertically Grown Few-Layer MoS2 Nanosheets on Hierarchical Carbon Nanocages for Pseudocapacitive Lithium Storage with Ultrahigh-Rate Capability and Long-Term Recyclability

Molybdenum disulfide (MoS₂) is an intensively studied anode material for lithium-ion batteries (LIBs) owing to its high theoretical capacity, but it is still confronted by severe challenges of unsatisfactory rate capability and cycle life. Herein, few-layer MoS₂ nanosheets, vertically grown on hierarchical carbon nanocages (hCNC) by a facile hydrothermal method, introduce pseudocapacitive lithium storage owing to the highly exposed MoS₂ basal planes, enhanced conductivity, and facilitated electrolyte access arising from good hybridization with hCNC. Thus, the optimized MoS₂/hCNC exhibits reversible capacities of 1670 mAh g⁻¹ at 0.1 A g⁻¹ after 50 cycles, 621 mAh g⁻¹ at 5.0 A g⁻¹ after 500 cycles, and 196 mAh g⁻¹ at 50 A g⁻¹ after 2500 cycles, which are among the best for MoS₂-based anode materials. The specific power and specific energy, which can reach 16.1 kW and 252.8 Wh after 3000 cycles, respectively, indicate great potential in high-power and long-life LIBs. These findings suggest a promising strategy for exploring advanced anode materials with high reversible capacity, high-rate capability, and long-term recyclability.     

Open‐cage fullerenes as tailor‐made container for a single water molecule

Water is the most important liquid on earth. Clusters of water have been investigated extensively in an effort to understand the bulk property of water. But the behavior of single water molecule without H‐bond has been rarely studied. Open‐cage [60]fullerenes have been shown to trap a single water molecule selectively over molecules with comparable size and act as the smallest “water bottle”. Copyright © 2013 John Wiley & Sons, Ltd.     

A highly selective dual-channel Hg2+ chemosensor based on an easy to prepare double naphthalene Schiff base

Science China Chemistry - A non-sulfur chemosensor based on an easy to prepare double naphthalene Schiff base is reported for the colorimetric and fluorometric dual-channel sensing of Hg2+ ions by...     

Development and testing of a Frisch-Grid Ionization Chamber for the measurement of low activity of alpha-particle emitters

Journal of Radioanalytical and Nuclear Chemistry - A Frisch-grid Ionization Chamber (FGIC) for the measurement of low activity of alpha-particle emitters has been built. The design and performance...     

Flow‐Injection Online Reduction Atomic Fluorescence Spectrometry Determination of Se(IV) and Se(VI) with Electrochemical Hydride Generation

Abstract

A new flow‐injection online reduction electrochemical hydride generation system for the determination of Se(IV) and Se(VI) by atomic fluorescence spectrometry (AFS) was developed. In the system, an electromagnetic induction oven was used as heating resource to reduce Se(VI) to Se(IV) and a homemade tubular electrolytic cell as hydride generator. All analytical procedures were automatically controlled by a computer. The conditions of online reduction, including temperature, HCl concentration, and reduction time, have been studied in detail. The detection limits (3σ) of Se(IV) and Se(VI) in aqueous solution were 0.26 µg L^?1 and 0.23 µg L^?1, respectively. The precision for 11 replicate measurements of 50 µg L^?1 Se(IV) and Se(VI) was 2.2% and 2.5%. This proposed method has been applied to the determination of Se(IV) and Se(VI) in springwater samples.