Archive for the ‘Nanoscale’ Category

Biomineralisation: Crystalline Calcium Carbonate

Tooth and claw

Biological structures such as teeth and bone are produced by a process called biomineralisation. The shape and structure of biominerals are controlled in an extremely precise way, from the nanoscale right up to the macroscopic level. The spontaneous formation of a tooth, claw, spine or shell is a truly amazing piece of chemistry, and unlocking the secrets of this could prove vital for materials scientists in their quest to engineer ever more complex nanostructures.

Biomineralisation of calcium carbonate

In  Nanoscale, we have recently published some papers on the formation of crystalline calcium carbonate (calcite) by biomineralisation. Yang et al., in their paper entitled ‘Biomineral nanoparticles are space filling’, present a study of biomineralisation in sea urchins, which contain spicules, spines and teeth (pictured left) all composed of calcium carbonate. They discuss the formation of crystalline biominerals through amorphous precursors, where one can imagine hydrated amorphous calcium carbonate nanoparticulate building blocks being able to flow and morph into the intricate shape of the final biomineral, followed by a period of dehydration and crystallization which forms the solid product. This process of dehydration and crystallization is discussed further by Rodriguez-Blanco et al., who used time-resolved X-ray diffraction in order to study the changes in crystal structure which occur when amorphous calcium carbonate crystallizes. They discovered that, under certain conditions, crystallization from the amorphous form to calcite occurs via another crystalline form, known as vaterite.

In November’s themed issue of Nanoscale, entitled Crystallization and Formation Mechanisms of Nanostructures, we published some other work on calcium biominarlisation, including studies of the formation and stability of amorphous calcium carbonate by Jiang et al. and Sommerdijk et al., and of calcium phosphate crystals by Mann et al., Taubert et al., Zhai et al., and Ibsen and Birkedal, which discussed the use of structure directing agents and organic additives to control crystal growth and morphology.

Papers like these are prime examples of how the study of natural processes can provide vital insight into the synthetic mechanisms which scientists are developing to produce new nanomaterials.

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Advances in Semiconductor Nanowires Research

Nanoscale is delighted to be collaborating with the International Conference on Materials for Advanced Technologies (ICMAT 2011) and will be publishing a collection of papers resulting from the high-quality research presented at the meeting on ‘Advances in Semiconductor Nanowires Research’.

Abstract submission deadline for ICMAT 2011: 15 January 2011

Deadline for submissions to the Nanoscale issue: 1 August 2011

Please indicate upon submission that your paper is from this conference. All articles will be subject to rigorous peer-review according to the journal’s usual standards.

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Hot article: DNA hybridization quantitative sensing

Hot Article – out now

Read about how the application of a combined approach of evanescent nanometry and force spectroscopy using magnetic tweezers helps quantify the degree of hybridization of a single synthetic single-stranded DNA oligomer to a resolution approaching a single-base.

Quantitative high-resolution sensing of DNA hybridization using magnetic tweezers with evanescent illumination
Piercen M. Oliver, Jin Seon Park and Dmitri Vezenov
Nanoscale, 2011, Advance Article
DOI: 10.1039/C0NR00479K

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Taking inspiration from the origin of life

On the origin of life

Professor Tony Ryan of the University of Sheffield visited the Royal Society of Chemistry in London to deliver a fascinating talk on Materials Chemistry and the Origin of Life. Professor Ryan described the origin of life in a ‘primordial soup’, fundamentally a mixture of organic building blocks such as sugars, fatty acids, amino acids and nucleotides, created by chemical reactions between methane, water, carbon dioxide and hydrogen cyanide (so the theory goes).

Watch the lecture now online: Materials Chemistry and the Origin of Life

Although it is not altogether clear how, from this soup sprung life, starting off as simple cells and eventually evolving into life as we know it today. Unimaginably complex molecules, structures, cells and organisms self-assemble from a simple list of ingredients, and give rise to the complex flora and fauna that is life on Earth. Professor Ryan went on to describe cell biology as ‘nanotechnology that works’, and indeed the internal workings of a cell are as a complex ‘nanosystem’ as we could ever hope to construct. He also discussed how, in his work, he has taken inspiration from the chemical basis of the ‘origin of life’, and used it directly in his materials chemistry research, a field which he refers to as ‘Soft Nanotechnology’.

From the bottom up

Current research in nanotechnology is striving towards heightened control and understanding of how to assemble complex and useful nanostructures. Just like the complex structures of living organisms self-assemble, we desire to be able to induce assembly of intricately designed and functional nanomaterials. In the decades since ‘bottom-up’ nanoparticle synthesis was pioneered, much attention has turned to the growth of anisotropic nanostructures. There has been a plethora of such structures reported in the literature, including tetrapods, wires, stars, nets and cages, amongst many others.

This month’s issue of Nanoscale, entitled ‘Crystallization and Formation Mechanisms of Nanostructures’, is a themed collection of papers which explore the various developments in solution-based crystal nucleation and growth mechanisms. In their editorial piece, Fiona Meldrum (University of Leeds, UK) and Helmut Cölfen (University of Konstanz, Germany) describe the synthesis of crystalline nanomaterials with well-defined sizes, morphologies and hierarchical structures as “one of the grand challenges of nanoscience and nanotechnology today”, but qualify this statement by explaining that “understanding of how these structures develop remains poor”. However, the works collected in this themed issue represent the state-of-the-art in our understanding of this field, and clearly illustrate that significant progress is being made in this fascinating, and fundamentally important, branch of science.

Meldrum and Cölfen go on to say that “it is also valuable to draw parallels between synthetic crystals, and their formation mechanisms, and crystals precipitated under biological control, namely biomaterials such as bones, teeth and seashells”. Again, inspiration can be taken from the complexity and beauty of these natural structures and used to shed further light on our studies in nanomaterial synthesis. The best efforts of synthetic chemists to control the growth, size and shape of nanomaterials pale in comparison with what occurs naturally in all living organisms. However, as we can presume we have only scratched the surface of possibilities here, one can anticipate that there remain many exciting discoveries and developments in this field of research.

Read the Nanoscale themed issue today for free: ‘Crystallization and Formation Mechanisms of Nanostructures

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Extracellular biosynthesis of silver nanoparticles

Extracellular biosynthesis‘HOT’ articleread for free now!!

The present study demonstrates an eco-friendly and low cost protocol for silver nanoparticles synthesis using cell-free filtrate of Aspergillus flavus.

Extracellular biosynthesis and characterization of silver nanoparticles using Aspergillus flavus NJP08: A mechanism perspective
Navin Jain, Arpit Bhargava, Sonali Majumdar, J. C. Tarafdar and Jitendra Panwar
Nanoscale, 2011, DOI: 10.1039/C0NR00656D

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Nanoparticles make leaves glow

glowing leavesCan street lights be replaced by trees? Taiwanese scientists believe that they can using gold nanoparticles to induce luminescence in leaves.

Yen Hsun Su and coworkers at Academia Sinica and the National Cheng Kung University in Taipei and Tainan have tackled this problem by synthesising gold nanoparticles shaped like sea urchins and diffusing them into plant leaves to create bio-LEDs.

Yuandi Li

Read this exciting Nanoscale paper today:
Influence of surface plasmon resonance on the emission intermittency of photoluminescence from gold nano-sea-urchins
Y. H. Su, S.-L. Tu, S.-W. Tseng, Y.-C. Chang, S.-H. Chang and W.-M. Zhang, Nanoscale, 2010
DOI: 10.1039/C0NR00330A

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New Advisory Board member for Nanoscale

We welcome our newest Advisory Board member, Professor Hong-Bo Sun from Jilin University.

Hong-Bo Sun obtained BS and PhD degrees in electronics from Jilin University. After spending some time in Japan, he returned to Jilin University to become a full professor in 2005.

His research in the passed 10 years has been focused on laser micro-nanofabrication, particularly in exploring novel laser technologies including direct writing and holographic lithography, as well as their applications on microoptics, micromachines, microfluids, and microsensors.

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We welcome Wei Lu to our Editorial Board

Nanoscale is pleased to announce the appointment of a new co-Editor-in-Chief, Professor Wei Lu.

Wei Lu graduated in physics from Tsinghua University, Beijing, China, from where he moved to Houston, Texas to obtain a PhD from Rice University.

He is currently an Assistant Professor in Electrical Engineering and Computer Science, at the University of Michigan. His research interest lies in the application and fundamental understanding of nanostructures and nanodevices, including high-density memory and logic devices based on two-terminal resistive switches (memristors), and semiconductor nanowire based electronics.

Professor Lu will join Professors Bai, Niederberger, Stellacci and Wang in handling Nanoscale submissions. Welcome!



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Nanoparticles, graphene and electrocatalysis

Communication

Highly dispersed ultrafine Pt and PtRu nanoparticles on graphene: formation mechanism and electrocatalytic activity
C. Nethravathi, E. A. Anumol, M. Rajamathi and N. Ravishankar
Nanoscale, 2011, Advance Article, DOI: 10.1039/C0NR00664E


Ravishankar and colleagues demostrate a strategy for obtaining a high dispersion of ultrafine Pt and PtRu nanoparticles on graphene.
This new methodology opens up new possibilities for the preparation of graphene-based hybrids for applications in multifunctional nanoscale devices.

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In vitro studies of a potential bone substitute

Just published

Two-layer membranes of calcium phosphate/collagen/PLGA nanofibres: in vitro biomineralisation and osteogenic differentiation of human mesenchymal stem cells

N Hild, O D Schneider, D Mohn, N A Luechinger, F M Koehler, S Hofmann, J R Vetsch, B W Thimm, R Müller and W J Stark

Nanoscale, 2011, DOI: 10.1039/C0NR00615G, Advance Article

A study evaluating the in vitro biomedical performance of a potential biomaterial that mimics bone tissue.

The material, a bilayer made of  poly(lactide-co-glycolide), calcium phosphate and collagen, could have applications in treatment of bone defects with complex geometries as wound dressing material.

Read the article now

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