RSC Advances

Tong, Jin-Qiang; Tian, Fang-Fang; Liu, Yi; Jiang, Feng-Lei

doi: 10.1039/c4ra09107hpmid: N/A

In this study, an acylhydrazone derivative, named N′-(2-chlorobenzylidene)-2-hydroxybenzo-hydrazide (NCH) has been synthesized by a one-pot synthesis method. Spectroscopy together with molecular modeling and electrochemistry were employed to investigate the binding behavior of NCH to serum albumin (SA), including human serum albumin (HSA) and bovine serum albumin (BSA), under physiological conditions. Unclassical static quenching has been proven in the fluorescence quenching of SA induced by NCH, due to the large activation energy requirement in the binding process. NCH was absorbed by both HSA and BSA with a 104 M−1 affinity constant. The primary binding driving force was the typical hydrophobic interaction occurring in Sudlow's site I of SA, while hydrogen bonds stabilized the NCH–SA complex and fixed the NCH configuration in the binding pocket. NCH could slightly destroy the polypeptide backbone and change the α-helix into an unordered ribbon. It was shown that NCH could efficiently bind with SA.

Passos, Marieta L. C.; Pereira, Mariana; Saraiva, M. Lúcia M. F. S.; Rangel, Maria; Moniz, Tania; Santos, João L. M.; Frigerio, Christian

doi: 10.1039/c4ra09748cpmid: N/A

This work proposes a new strategy for the immobilization of semiconductor nanocrystals by carrying out simultaneously the synthesis of silica nanostructures and the encapsulation of MPA-capped CdTe quantum dots (QDs). The developed approach was bioinspired by the naturally occurring biosilicification process that some organisms, like diatoms and sponges, use to produce nanostructures of silica, and prevents the use of harsh and environmentally unfriendly conditions such as toxic and expensive organic solvents, high temperature and pressure and extreme pH values. Different parameters that could influence the silica particle synthesis and the QD immobilization, such as silica precursors, catalysts and ions concentration, pH and amount of QDs were evaluated. Encapsulation efficiency, size and the shape of biosilica structures were also determined by the experimental conditions. Immobilization and QD concentration has a strong impact on QD fluorescence and on the silica–QDs nanostructure stability.

Dange, Nitin S.; Hong, Bor-Cherng; Lee, Gene-Hsiang

doi: 10.1039/c4ra10222cpmid: N/A

A concise synthesis of yuehchukene has been achieved using organocatalytic Friedel–Crafts alkylation of indole to a sterically encumbered α-alkyl enal as the key step. A racemization process during the subsequent cyclization steps of the conjugate adduct to yuehchukene was observed.

Vaghela, Chetana; Kulkarni, Mohan; Karve, Meena; Aiyer, Rohini; Haram, Santosh

doi: 10.1039/c4ra08688kpmid: N/A

The present communication reports the development of processable polyaniline (PANI) in the film form via agarose–guar gum (A–G) assisted in situ polymerization of aniline using potassium dichromate as an oxidant. The network structure of A–G not only provides the mechanical support to polyaniline, but also a microporous template, which allows the reinforcement of PANI into nanostructures with an interpenetrated polymer network between PANI and A–G, as evidenced by optical microscopy and SEM. The FTIR and TGA analysis confirms the formation of an agarose–guar gum–polyaniline composite (A–G–PANI) having hydrogen bonding interactions. The A–G–PANI film has better adherence property on the glass substrate as compared with PANI. The A–G–PANI composite shows appreciable DC conductivity in the range of 10−3–10−2 S cm−1 and electrochemical activity, having oxidation–reduction transitions corresponding to polyaniline. It exhibits both ionic and electronic conductivity as confirmed by EIS. The electro-responsive characteristics exhibited by the novel A–G–PANI composite make it a promising electrode material for the construction of chemical sensors and biosensors.

Chumnanvej, Napasawan; Samakkanad, Natthapol; Pohmakotr, Manat; Reutrakul, Vichai; Jaipetch, Thaworn; Soorukram, Darunee; Kuhakarn, Chutima

doi: 10.1039/c4ra11703dpmid: N/A

A novel OXONE® mediated direct difunctionalization of alkenes with NaNO2 in aqueous acetonitrile for the synthesis of α-nitrooximes was developed. The α-nitrooximes were readily prepared in moderate to high yields at room temperature under mild reaction conditions. The present protocol offers an easy and environmentally benign approach to access various α-nitrooximes derived from styrene derivatives.

Du, Yingying; Yang, Ping; Chen, Hsueh-Shih; Che, Quande; Liu, Yunshi; He, Haiyan; Miao, Yanping; Zhao, Jie

doi: 10.1039/c4ra08770dpmid: N/A

Highly luminescent hydrophobic CdSe and CdSe/CdxZn1−xS quantum dots (QDs) were synthesized via an organic route. The phase transfer of the QDs was carried out through a ligand exchange from 3-aminopropyltrimethoxysilane (APS) instead of an organic capping agent to get aqueous QDs. A functional sol–gel SiO2 sol with a high QD concentration was obtained from the aqueous QD colloidal solution with APS through the hydrolysis and condensation which subsequently occurred. Flexible inorganic SiO2 films with QDs were fabricated via various methods. The photodegradation experiments of the resulting films were completed. It is surprising that the QDs in films were revealed to be highly stable. Especially, the PL intensity of the films increased dramatically after irradiation by 365 nm UV light. By integrating a thin CdSe QD–silica film on a solar cell, the enhanced current demonstrated that a thin film can facilitate the continuous development of solar cells. Because of their high PL brightness, multicolor emission, flexibility and stability, these films will have great potential applications.

Mu, Wanjun; Xie, Xiang; Zhang, Rui; Li, Xingliang; Lv, Kai; Yu, Qianhong; Wei, Hongyuan; Jian, Yuan

doi: 10.1039/c4ra07575gpmid: N/A

Li-doped WO3 nanowires have been hydrothermally prepared and characterized mainly via spectroscopic methods. Both the hexagonal structure distortion and morphology evolution induced by Li doping reveal a lattice expansion of about 0.07 Å. Also, the residence of oxygen vacancy and the enlargement of external surface areas positively correlate with the narrowing of energy band. Subsequently, the electrocatalytic oxidation of ascorbic acid using a Li-doped WO3 film-coated electrode performs a 13% and 21% negative shift of the oxidation overpotential compared with a WO3 film-coated electrode and a bare glassy carbon electrode, respectively. A preliminary mechanism has been proposed on the basis of relevant model analyses.

Bessières, Maxime; Roy, Vincent; Agrofoglio, Luigi A.

doi: 10.1039/c4ra13033bpmid: N/A

Protected pyrimidine nucleobases are of major importance as intermediates in the synthesis of nucleoside analogues and molecules with biological interests. We describe herein a novel practical microwave-assisted N-Boc protection of pyrimidine nucleobases under mild conditions using silica gel, avoiding treatment steps, and in increased yield.

Li, Jie; Wang, Naixin; Yan, Hao; Ji, Shulan; Zhang, Guojun

doi: 10.1039/c4ra10655epmid: N/A

Inspired by the complementary roles of surface energy and roughness on natural nonwetting surfaces, a superhydrophobic surface has been successfully designed and prepared by self-assembled monolayer modification on a hierarchical ZIF-8/polymer hybrid membrane. The as-prepared membrane exhibited the best overall performance for n-butanol pervaporation.

Yang, Huimin; Cui, Xinjiang; Deng, Youquan; Shi, Feng

doi: 10.1039/c4ra11148fpmid: N/A

The aerobic oxidation of benzylic and allylic alcohols has been realized with carbon material as the catalyst in the absence of transition-metal and heteroatoms. Under the optimized reaction conditions, aldehyde and acid can be selectively synthesized with up to 99% yields. The carbon catalyst can be easily recovered from the reaction mixture and can be reused for 5 runs without deactivation.