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Qiaofeng Yao, Victor Fung, Cheng Sun, Sida Huang, Tiankai Chen, De-En Jiang, Jim Yang Lee, Jianping Xie
Atom-by-atom engineering of nanomaterials requires atomic-level knowledge of the size evolution mechanism of nanoparticles, which remains one of the greatest mysteries in nanochemistry. Here we reveal atomic-level dynamics of size evolution reaction of molecular-like nanoparticles, i.e., nanoclusters (NCs) by delicate mass spectrometry (MS) analyses. The model size-conversion reaction is [Au23 (SR)16 ]- → [Au25 (SR)18 ]- (SR = thiolate ligand). We demonstrate that such isoelectronic (valence electron count is 8 in both NCs) size-conversion occurs by a surface-motif-exchange-induced symmetry-breaking core structure transformation mechanism, surfacing as a definitive reaction of [Au23 (SR)16 ]-  + 2 [Au2 (SR)3 ]- → [Au25 (SR)18 ]-  + 2 [Au(SR)2 ]- ...
May 17, 2018: Nature Communications
Jing Sun, Chong Qiu, Yiping Diao, Wei Wei, Hongwei Jin, Yi Zheng, Jiancheng Wang, Lihe Zhang, Zhenjun Yang
Small interfering RNA (siRNA) has been continuously explored for clinical applications. However, neither nanocarriers nor conjugates have been able to remove the obstacles. In this study, we employed a combined nanochemistry strategy to optimize its delivery dilemma, where different interactions and assembly modes were cooperatively introduced into the forming process of siRNA/lipids nanoplexes. In the nanoplexes, the 3',3″-bis-peptide-siRNA conjugate (pp-siRNA) and gemini-like cationic lipids (CLDs) were employed as dual regulators to improve their bio-behavior...
March 2, 2018: Molecular Therapy. Nucleic Acids
Agustín Lorenzo, Waldemar A Marmisollé, Eliana M Maza, Marcelo Ceolín, Omar Azzaroni
Molecular design and preparation of redox active films displaying mesoscopic levels of organization represents one of the most actively pursued research areas in nanochemistry. These mesostructured materials are not only of great interest at the fundamental level because of their unique properties but they can also be employed for a wide range of applications such as electrocatalysts, electronic devices, and electrochemical energy conversion and storage. Herein, we introduce a simple and straightforward strategy to chemically modify electrode surfaces with self-assembled electroactive polyelectrolyte-surfactant complexes...
March 14, 2018: Physical Chemistry Chemical Physics: PCCP
Edwin A Baquero, Simon Tricard, Yannick Coppel, Juan C Flores, Bruno Chaudret, Ernesto de Jesús
The synthesis of metal nanoparticles (NPs) under controlled conditions in water remains a challenge in nanochemistry. Two different approaches to obtain platinum NPs, which involve the treatment of aqueous solutions of preformed sulfonated (NHC)Pt(ii) dimethyl complexes with carbon monoxide, and of (NHC)Pt(0) diolefin complexes with dihydrogen (NHC = N-heterocyclic carbene), are disclosed here. The resulting NPs were found to be highly stable in water under air for an indefinite time period. Coordination of the NHC ligands to the platinum surface via the carbenic carbon was monitored by solid-state NMR spectroscopy, and the presence of a platinum-carbon bond was unambiguously evidenced by the determination of a 13 C-195 Pt coupling constant (1106 and 1050 Hz for NPs containing 13 C labeled-NHC ligands and prepared under CO and H2 , respectively)...
March 28, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Min-Quan Yang, Jing Wang, Hao Wu, Ghim Wei Ho
The fast development of nanoscience and nanotechnology has significantly advanced the fabrication of nanocatalysts and the in-depth study of the structural-activity characteristics of materials at the atomic level. Vacancies, as typical atomic defects or imperfections that widely exist in solid materials, are demonstrated to effectively modulate the physicochemical, electronic, and catalytic properties of nanomaterials, which is a key concept and hot research topic in nanochemistry and nanocatalysis. The recent experimental and theoretical progresses achieved in the preparation and application of vacancy-rich nanocatalysts for electrochemical water splitting are explored...
April 2018: Small
Elisabete Oliveira, Emilia Bértolo, Cristina Núñez, Viviane Pilla, Hugo M Santos, Javier Fernández-Lodeiro, Adrian Fernández-Lodeiro, Jamila Djafari, José Luis Capelo, Carlos Lodeiro
Red and green are two of the most-preferred colors from the entire chromatic spectrum, and red and green dyes are widely used in biochemistry, immunohistochemistry, immune-staining, and nanochemistry applications. Selective dyes with green and red excitable chromophores can be used in biological environments, such as tissues and cells, and can be irradiated with visible light without cell damage. This critical review, covering a period of five years, provides an overview of the most-relevant results on the use of red and green fluorescent dyes in the fields of bio-, chemo- and nanoscience...
January 2018: ChemistryOpen
Sabrina Engel, Nadja Möller, Bart Jan Ravoo
The design of multifunctional nanomaterials that respond to external stimuli and mimic the capacity of biological materials to respond and adapt to their environment has become a focus of interest in nanotechnology. In this Concept, we describe the development of supramolecular nanoparticle assemblies constructed by use of host-guest interactions between cyclodextrins and suitable guest molecules. The nanoparticle assembly is reversible and can be directed by applying different stimuli that act either on the guest molecules or the nanoparticles...
December 18, 2017: Chemistry: a European Journal
Roberto Fernandez-Alvarez, Vladimír Ďorďovič, Mariusz Uchman, Pavel Matějíček
Anionic boron cluster compounds (ABCCs) are intrinsically amphiphilic building blocks suitable for nanochemistry. ABCCs are involved in atypical weak interactions, notably dihydrogen bonding, due to their peculiar polyhedral structure, consisting of negatively charged B-H units. The most striking feature of ABCCs that differentiates them from typical surfactants is the lack of head-and-tail structure. Furthermore, their structure can be described as intrinsically amphiphilic or aquaneutral. Therefore, classical terms established to describe self-assembly of classical amphiphiles are insufficient and need to be reconsidered...
December 7, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Jing Xia, Z Ryan Tian, Licheng Hua, Lei Chen, Zhongrong Zhou, Linmao Qian, Peter S Ungar
The nanoscale responses of teeth to chewing loads are poorly understood. This has contributed to debate concerning the aetiology of enamel wear and resistance to fracture. Here we develop a new model for reactions of individual hydroxyapatite nanofibres to varying loads and directions of force. Hydroxyapatite nanofibres, or crystallites, composed of chains of bonded nanospheres, are the fundamental building blocks of enamel. This study indicates that these nanofibres respond to contact pressure in three distinct ways depending on force magnitude and direction: (i) plucking (nanosphere loss when the strength of the bonding protein 'glue' is exceeded), (ii) plastic deformation (compression to gradually bend nanofibres and squeeze the protein layer), and (iii) fragmentation (nanofibres fracture when the strength of H-bonds that bind smaller nanoparticles into nanospheres is exceeded)...
October 2017: Journal of the Royal Society, Interface
Jia Jia, Hong Wang, Zhuole Lu, Paul G O'Brien, Mireille Ghoussoub, Paul Duchesne, Ziqi Zheng, Peicheng Li, Qiao Qiao, Lu Wang, Alan Gu, Abdinoor A Jelle, Yuchan Dong, Qiang Wang, Kulbir Kaur Ghuman, Thomas Wood, Chenxi Qian, Yue Shao, Chenyue Qiu, Miaomiao Ye, Yimei Zhu, Zheng-Hong Lu, Peng Zhang, Amr S Helmy, Chandra Veer Singh, Nazir P Kherani, Doug D Perovic, Geoffrey A Ozin
This study has designed and implemented a library of hetero-nanostructured catalysts, denoted as Pd@Nb2 O5 , comprised of size-controlled Pd nanocrystals interfaced with Nb2 O5 nanorods. This study also demonstrates that the catalytic activity and selectivity of CO2 reduction to CO and CH4 products can be systematically tailored by varying the size of the Pd nanocrystals supported on the Nb2 O5 nanorods. Using large Pd nanocrystals, this study achieves CO and CH4 production rates as high as 0.75 and 0.11 mol h-1 gPd -1 , respectively...
October 2017: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
Bin Ai, Zengyao Wang, Helmuth Möhwald, Gang Zhang
We show that the growth of Ag nanoparticles (NPs) follows the areas of maximum plasmonic field in nanohole arrays (NAs). We thus obtain Ag NP rings not connected to the metallic rim of the nanoholes. The photocatalytic effect resulting from the enhanced E-field of NAs boosts the reaction and is responsible for the site selectivity. The strategy, using plasmonics to control a chemical reaction, can be expanded to organic reactions, for example, synthesis of polypyrrole. After the NA film is removed, ordered ring-shaped Ag NPs are easily obtained, inspiring a facile micropatterning method...
December 26, 2017: ACS Nano
Qiaofeng Yao, Xun Yuan, Victor Fung, Yong Yu, David Tai Leong, De-En Jiang, Jianping Xie
The continuous development of total synthesis chemistry has allowed many organic and biomolecules to be produced with known synthetic history-that is, a complete set of step reactions in their synthetic routes. Here, we extend such molecular-level precise reaction routes to nanochemistry, particularly to a seed-mediated synthesis of inorganic nanoparticles. By systematically investigating the time-dependent abundance of 35 intermediate species in total, we map out relevant step reactions in a model size growth reaction from molecularly pure Au25 to Au44 nanoparticles...
October 13, 2017: Nature Communications
Younan Xia, Xuan Yang
Waste not, want not. There is a pressing need to maximize the use of precious metals in catalysts to attain affordable and sustainable products. Recent progress in nanochemistry suggests that it is feasible to put the majority of metal atoms in a catalytic particle to work at optimal activity and selectivity.
March 21, 2017: Accounts of Chemical Research
Jian Zhang, Jing Xu, Yan Wang, Huaiguo Xue, Huan Pang
This account mainly introduces and reviews our recent progress in three projects: antibacterial nanomaterial, electrocatalyst for detecting and electrode nanomaterial of energy storage device, especially the supercapacitor. Besides, our thought and idea about the design, fabrication and application of corresponding nanomaterials are sketched throughout the whole article in order to reveal the structure-function relationship and corresponding mechanism. In the end, we tend to attach importance to the bottleneck of nanomaterial's development and put forward our understanding in this field...
January 2018: Chemical Record: An Official Publication of the Chemical Society of Japan ... [et Al.]
Peiyuan Wang, Jing Tian, Jiulin Hu, Xuejun Zhou, Chilin Li
Large-capacity conversion electrodes are highly required to raise the energy density of batteries. However, their undesired phase segregation and volume expansion during cycling lead to the motivation for nanofabrication and nanochemistry of active species in order to decrease "dead mass" and promote better construction of conductive networks. However, the inactivity of the conductive skeleton and loose nanostructure would compromise the energy density of the electrode. The integration of large-sized (high-density) grains into an electroactive conductive network in a compact way is still a big challenge...
July 25, 2017: ACS Nano
Christopher H Hendon, Keith T Butler, Alex M Ganose, Yuriy Román-Leshkov, David O Scanlon, Geoffrey A Ozin, Aron Walsh
The archetypal silica- and aluminosilicate-based zeolite-type materials are renowned for wide-ranging applications in heterogeneous catalysis, gas-separation and ion-exchange. Their compositional space can be expanded to include nanoporous metal chalcogenides, exemplified by germanium and tin sulfides and selenides. By comparison with the properties of bulk metal dichalcogenides and their 2D derivatives, these open-framework analogues may be viewed as three-dimensional semiconductors filled with nanometer voids...
April 25, 2017: Chemistry of Materials: a Publication of the American Chemical Society
Qi Li, Tian-Yi Luo, Michael G Taylor, Shuxin Wang, Xiaofan Zhu, Yongbo Song, Giannis Mpourmpakis, Nathaniel L Rosi, Rongchao Jin
Compared to molecular chemistry, nanochemistry is still far from being capable of tailoring particle structure and functionality at an atomic level. Numerous effective methodologies that can precisely tailor specific groups in organic molecules without altering the major carbon bones have been developed, but for nanoparticles, it is still extremely difficult to realize the atomic-level tailoring of specific sites in a particle without changing the structure of other parts (for example, replacing specific surface motifs and deleting one or two metal atoms)...
May 2017: Science Advances
Mady Elbahri, Ramzy Abdelaziz, Duygu Disci-Zayed, Shahin Homaeigohar, Justyna Sosna, Dieter Adam, Lorenz Kienle, Torben Dankwort, Moheb Abdelaziz
The dynamic underwater chemistry seen in nature is inspiring for the next generation of eco-friendly nanochemistry. In this context, green synthesis of size-tailored nanoparticles in a facile and scalable manner via a dynamic process is an interesting challenge. Simulating the volcano-induced dynamic chemistry of the deep ocean, here we demonstrate the Leidenfrost dynamic chemistry occurring in an underwater overheated confined zone as a new tool for customized creation of nanoclusters of zinc peroxide. The hydrodynamic nature of the phenomenon ensures eruption of the nanoclusters towards a much colder region, giving rise to growth of monodisperse, size-tailored nanoclusters...
May 12, 2017: Nature Communications
Nohad Gresh, Sehr Naseem-Khan, Louis Lagardère, Jean-Philip Piquemal, Judit E Sponer, Jiri Sponer
Stacking of guanine quartets (GQs) can trigger the formation of DNA or RNA quadruple helices, which play numerous biochemical roles. The GQs are stabilized by alkali cations, mainly K(+) and Na(+), which can reside in, or channel through, the central axis of the GQ stems. Further, ion conduction through GQ wires can be leveraged for nanochemistry applications. G-quadruplex systems have been extensively studied by classical molecular dynamics (MD) simulations using pair-additive force fields or by quantum-chemical (QC) calculations...
April 13, 2017: Journal of Physical Chemistry. B
Kasper P Kepp
Gold plays a major role in nanochemistry, catalysis, and electrochemistry. Accordingly, hundreds of studies apply density functionals to study chemical bonding with gold, yet there is no systematic attempt to assess the accuracy of these methods applied to gold. This paper reports a benchmark against 51 experimental bond enthalpies of AuX systems and seven additional polyatomic and cationic molecules. Twelve density functionals were tested, covering meta functionals, hybrids with variable HF exchange, double-hybrid, dispersion-corrected, and nonhybrid GGA functionals...
March 9, 2017: Journal of Physical Chemistry. A
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