Archive for the ‘Nanoscale’ Category

Highlights from ChinaNANO

The Nanoscale Editorial Office is delighted at the success of the Nanoscience Symposium which occurred at the ChinaNANO 2015 conference in Beijing from 3rd-5th September. This one-day symposium included talks from the Nanoscale Associate Editors about their latest research covering topics such as carbon nanomaterials, nanoelectronics, bionanomaterials, nanophotonics, nanoclusters and nanocrystals.

Some articles submitted to Nanoscale from delegates of the ChinaNANO 2015 conference can be found below.

Surface coating of siRNA-peptidomimetic nano-self-assemblies with anionic lipid bilayers: Enhanced gene silencing and reduced adverse effects in vitro
Xianghui Zeng, Anne Marit de Groot, Alice Sijts, Femke Broere, Erik Oude Blenke, Stefano Colombo, Willem van Eden, Henrik Franzyk, Hanne M Nielsen and Camilla Foged
Nanoscale, 2015, DOI: 10.1039/C5NR04807A

Strong metal-support interaction in novel core-shell Au-CeO2 nanostructures induced by different pretreatment atmospheres and its influence on CO oxidation
Zhihua Wang, Huifen Fu, Ziwei Tian, Dongmei Han and Fubo Gu
Nanoscale, 2015, DOI: 10.1039/C5NR06929G

Fabrication of ultra-thin silicon nanowire arrays using ion beam assisted chemical etching
Zhiyuan Tan, Wenjia Shi, Chungang Guo, Quan Zhang, Liang Yang, Xiaoling Wu, Guo-an Cheng and Ruiting Zheng
Nanoscale, 2015,7, 17268-17273, DOI: 10.1039/C5NR02876K

Ethanol-assisted gel chromatography for single-chirality separation of carbon nanotubes
Xiang Zeng, Jinwen Hu, Xiao Zhang, Naigen Zhou, Weiya Zhou, Huaping Liu and Sishen Xie
Nanoscale, 2015,7, 16273-16281, DOI: 10.1039/C5NR04116C

There was a great turn-out and we received a lot of useful feedback from the attendees.

A prominent highlight of the event was the reception organised by the Royal Society of Chemistry to celebrate the launch of Nanoscale Horizons as well as the Nanoscale and Nanoscale Horizons partnership with the National Center for Nanoscience and Technology (NCNST) in Beijing which included cutting an enormous cake!

Left to right: Xiaodong Chen, Fiona McKenzie, Chunli Bai and Xingyu Jiang

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Micro meets nano: Multicolour gold nanoprobes detect micoRNA biomarkers in serum

Researchers from Chinese Academy of Sciences have investigated the use of molecular beacons (MBs) for the simultaneous detection of multiple microRNA (miRNA) biomarkers.

The MBs were immobilized onto gold nanoparticles (AuNPs) via poly-adenine (poly-A) spacer. In addition, the authors used short oligonucleotides (oligos) consisting of 5 As in order to fill the gaps between MBs on the AuNP surface to ensure stability in salt solutions and obtain greater fluorescence signals.

MBs with 3 different fluorophores were employed in order to enable multiplexed detection of miRNAs in simulated serum samples. The authors reported that each MB specifically bound to its corresponding miRNA target in the presence of 10% fetal bovine serum (FBS), thereby demonstrating the applicability of this method for real biological sample detection.

In recent years, miRNA has emerged as a potential biomarker for many types of diseases, such as cancer, neurological disorders and cardiovascular disease. The need for rapid and sensitive assays for miRNA detection is therefore of great interest. Wang et al. have demonstrated a step in this direction with the research presented here.

Elaborately designed diblock nanoprobes for simultaneous multicolor detection of microRNAs
Chenguang Wang, Huan Zhang, Dongdong Zeng, Wenliang Sun, Honglu Zhang, Ali Aldalbahi, Yunsheng Wang, Lili San, Chunhai Fan, Xiaolei Zuo and Xianqiang Mi
Nanoscale, 2015,7, 15822-15829, DOI: 10.1039/C5NR04618A

Dr Lee Barrett is a guest web writer for the Nanoscale blog. Lee is currently a postdoctoral researcher in the Centre for Molecular Nanometrology at the University of Strathclyde. His research is currently focused on the development of nanoparticle-based sensors and surface enhanced Raman scattering (SERS). Follow him on twitter @L_Bargie

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HOT article: Microgel coating of magnetic nanoparticles via bienzyme mediated free-radical polymerization for colorimetric detection of glucose

Researchers from Qigang Wang’s group have developed a new strategy for the fabrication of core shell magnetic microgels for glucose detection, which is one of the most frequently used tests in clinical environments. Magnetic nanoparticles containing carboxylic acid groups on the surface were used as a starting material to covalently bind the enzyme glucose oxidase (GOx). A second enzyme, horseradish peroxidase, was also attached through a bifunctional polyethylene glycol polymer which ensured a working distance between the two immobilised enzymes. The microgels could be formed by adding glucose and acetylacetone (ACAC) with PEGMA and crosslinker PEGDA. One of the by-products of glucose oxidation, hydrogen peroxide, reacts with ACAC to form radicals that polymerise the monomers resulting in a gel-like coating formed around the enzyme containing particles.

The preparation of the magnetic core–shell microgels.

After polymerisation the enzymes retained their reactivity. Even after 7 days storage, 96% catalytic activity was observed with respect to a fresh sample. The high selectivity towards glucose was demonstrated with other sugars e.g. fructose, lactose and maltose. It is thought that this strategy could be extended to the detection of other biomolecules through new oxidase-HRP systems, as well as being easily translatable to clinical fields.

Microgel coating of magnetic nanoparticles via bienzyme-mediated free-radical polymerization for colorimetric detection of glucose
Qing Wu, Xia Wang, Chuanan Liao, Qingcong Wei and Qigang Wang
Nanoscale, 2015,7, 16578-16582. DOI: 10.1039/C5NR05716G

Dr Mike Barrow is a guest web writer for the Nanoscale blog, he currently works as a Postdoctoral Researcher at the University of Liverpool. Twitter: @mikesyb

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Call for Nanotechnology Data Reporting Guidelines

Dr. Mervi Heiskanen

Dr. Stephanie Morris

The authors of this article are both Program Managers based at the US National Cancer Institute’s (NCI) Center for Biomedical Informatics and Information Technology and Office of Cancer Nanotechnology Research, respectively, working towards improving quality of and access to published experimental data.

In recent years, there has been increasing interest in improving how nanomaterials are defined and characterized due to a lack of specific nano-related metadata standards in the Nanotechnology field. The nano-community agrees data reporting guidelines would facilitate data reproducibility and reuse.

The recent collaboration between Elsevier Journals and the NCI cancer Nanotechnology Laboratory (caNanoLab) data portal is an important step towards providing researchers with easy access to high quality nanotechnology data for reproduction and re-use. However, access to data is only useful if information about experimental details is available. Is there something we can do to improve usability of nanotechnology data?

The lack of high quality nanotechnology research data is a known challenge, further complicated by the diversity and growing number of nanomaterials. The OMICs communities (e.g., genomics and proteomics) have pioneered the development of databases such as the Gene Expression Omnibus (GEO) Database and the Worldwide Protein Data Bank (wwPDB), as well as standard guidelines for recording data. These guidelines define the minimum information that must be reported and stored, and facilitate data reproducibility and integration across different datasets to enable further analysis by the research community. Many of these reporting guidelines can be accessed at Biosharing, and are required by journals for data deposition during the manuscript submission process.

Several STM journals already require authors to adhere to minimum characterization requirements, particularly when reporting new chemical compounds, which reviewers are asked to evaluate to ensure reproducibility and reliability of the research. Nature and its sister journals have further enforced this for their life science articles by implementing an initiative which includes the submission of a checklist by authors intended to remind them to provide sufficient experimental details to enable reproducibility. However, we need to agree on a nanotechnology-specific checklist, and extend the reproducibility initiative to include other relevant journals. This needs to be a collaborative effort driven by the research community, editors and publishers, regulatory agencies, and funding organizations in order for this to become common practice and lead to improvements in data reuse.

The nanotechnology community is in the early stages of defining metadata that should be included in data submissions, and recognizes the metadata will differ by research field (e.g., biomedicine, ecological studies, and health and safety). Examples of nanomaterial databases working towards this goal include caNanoLab, which uses MinChar, and the Nanomaterial Registry’s Minimal Information about Nanomaterials (MIAN). However, there is no common minimal information guideline agreed upon by the larger nanotechnology community. The need for the development of a common reporting recommendation has been recognized by the NCI Nanotechnology Working Group (NCI Nano WG). With active participants from federal institutions, academia, and industry, primarily from the US and the NanoSafety Cluster in Europe, the NCI Nano WG can serve as a coordinating body for collecting community input across nanotechnology research fields. A nanotechnology minimal information standard is also of great interest to the US National Nanotechnology Initiative, which has developed a signature initiative on nanoinformatics (Nanotechnology Knowledge Infrastructure) that works with the nanotechnology community to provide resources and tools.

We believe that data submission guidelines combined with better access to data will improve data quality and reproducibility and will ultimately translate to advances in areas such as biomedical research, environmental safety, and nanomanufacturing. Collaboration and coordination among all stakeholders is needed to ensure data submission guidelines benefit all parties.

If everyone is moving forward together, then success takes care of itself.” – Henry Ford

DisclosureViews expressed in this web article are those of the authors and do not necessarily reflect the views or polices of the Department of Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government.

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Hybrid nanoparticles: The fight against breast cancer heats up

Gold nanorods with cisplatin-polypeptide wrapping were developed for combinational photothermal therapy and chemotherapy of triple negative breast cancer.

Researchers from China have advanced the fight against breast cancer (BC) by developing a method that targets triple negative breast cancer (TNBC) – a highly aggressive subtype of BC and a form that is challenging to completely eradicate.

Their method consisted of the formation of gold nanorods (GNRs) with a cisplatin-polypeptide wrapping and folic acid (FA) functionalization (FA-GNR@Pt) for the simultaneous targeted photothermal therapy and chemotherapy. These hybrid nanoparticles combine the photothermal conversion properties of GNRs, superior biocompatibility of polypeptide poly(L-glutamic acid) (PGA), chemotoxicity of cisplatin and the tumour targeting ability of FA.  FA-GNR@Pt nanoparticles exhibited temperature increases both in vitro and in vivo using 655 nm NIR laser irradiation and, in combination with systemic administration in mice, were able to inhibit the proliferation and lung metastisis of the 4T1 breast tumour.

The research presented here takes significant steps in furthering the understanding of breast cancer, particularly TNBC, which have increased risk of metastisis.

Near infrared light-actuated gold nanorods with cisplatin–polypeptide wrapping for targeted therapy of triple negative breast cancer
Bing Feng, Zhiai Xu, Fangyuan Zhou, Haijun Yu, Qianqian Sun, Dangge Wang, Zhaohui Tang, Haiyang Yu, Qi Yin, Zhiwen Zhang and Yaping Li
Nanoscale, 2015, 7, 14854-14864.  DOI: 10.1039/C5NR03693C

Dr Lee Barrett is a guest web writer for the Nanoscale blog. Lee is currently a postdoctoral researcher in the Centre for Molecular Nanometrology at the University of Strathclyde. His research is currently focused on the development of nanoparticle-based sensors and surface enhanced Raman scattering (SERS). Follow him on twitter @L_Bargie.

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HOT article: Nanostructured conducting polymer hydrogels for energy storage applications

Future energy storage solutions require a combination of high energy density, high reliability and low manufacturing cost. Conducting polymer hydrogels (CPHs) have emerged in recent years as a viable alternative for energy storage applications, as a Feature article by Shi et al. reports.

CPHs exhibit highly advantageous properties such as a large surface area, tunable mechanical properties and high conductivity compared to other polymers. These materials combine a conductive π–conjugated backbone with a porous structure.

Two synthesis routes are presented: template-guided synthesis (e.g. polymerization of monomers in a non-conductive hydrogel matrix) and direct formation using phytic acid as a gelator and dopant of the polymer.

Independent of synthesis route, CPHs were successfully demonstrated as bulk materials for electrochemical capacitors (also termed “supercaps”), as well as functional binders within Li-ion batteries. By careful modification of the polymer properties, a stable material able to withstand over 10000 charge-discharge cycles was demonstrated. Finally, the current hurdles for mass-market adoption, such as limited mechanical strength, lower conductivity than currently utilized material combinations and a lower capacity are explained, and paths to overcome these are discussed.

Nanostructured conducting polymer hydrogels for energy storage applications
Ye Shi, Lele Peng and Guihua Yu
Nanoscale, 2015, 7, 12796-12806. DOI: 10.1039/C5NR03403E

Sebastian Axmann is a guest web-writer for the Nanoscale blog. His interests comprise manufacturing and metrology of nanostructures as well as their usage in current semiconductor devices. He also posts links to interesting research articles on Twitter: @SebastianAxmann.

Nanoscale, 2015,7, 12796-12806
DOI: 10.1039/C5NR03403E

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HOT article: Bridging the transport pathway of charge carriers in a Ta3N5 nanotube array photoanode for solar water splitting

Besides the wide field of photovoltaics research, additional technologies, such as the direct conversion of H2 via solar water splitting, are currently being researched. A recent article by Zhang et al. presents their findings on improved manufacturing routes for these cells.

For the time being, Ta3N5 is the material of choice as the band gap and structure are both well suited for light absorption. To form a large interfacial area for efficient light conversion within the cells, arrays of hollow nanorods are employed. As the authors describe in their article, earlier attempts of a one-step synthesis route, also evaluated by other researchers, led to weak adhesion of the brittle nanorod film on the substrate. Their new approach utilizes a two-step synthesis route: first, a nanorod layer of Ta2O5 is formed via anodization in a solution with a lower HF concentration compared to that employed by other groups. Next, this weakly adhering layer is removed by sonication and a second layer is formed. The formation of the second layer also employs a low reaction temperature to limit the reaction rate. Finally, this second nanorod layer is nitridated, forming Ta3N5 from the Ta2O5 layer.

(a) Schematic illustration of the synthetic process, (b) top-view SEM image and (c) cross-sectional SEM image of Ta3N5 NTAs.

The resulting layer was found to adhere well on the substrate surface and to exhibit only a few cracks. By further optimization of processing times and the additive material used during nitridation, a maximum current density of 11 mA/cm² at 1.6 V was demonstrated by the authors.

Bridging the transport pathway of charge carriers in a Ta3N5 nanotube array photoanode for solar water splitting
Peng Zhang, Tuo Wang, Jijie Zhang, Xiaoxia Chang and Jinlong Gong
Nanoscale, 2015, Advance Article. DOI: 10.1039/C5NR03013G

Sebastian Axmann is a guest web-writer for the Nanoscale blog. His interests comprise manufacturing and metrology of nanostructures as well as their usage in current semiconductor devices. He also posts links to interesting research articles on Twitter: @SebastianAxmann.

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HOT article: Reversible control of pore size and surface chemistry of mesoporous silica through dynamic covalent chemistry: philicity mediated catalysis

Reversible engineering of the pore size and philicity of mesoporous SBA via dynamic covalent chemistry triggered by changes in pH.

Control of surface chemistry is important for utilisation of mesoporous silicas in many applications such as catalysis, drug delivery and separation sciences. Due to the mostly irreversible nature of covalent functionalisations and lack of rigidity in supramolecular approaches, in this study, dynamic covalent chemistry was used to reversibly alter the chemical coating on the surface of amine functional mesoporous silica SBA-15. This was achieved through the condensation reaction of the primary amine on SBA-15 with 4-decyloxybenzaldehyde (4-DB) to form an imine containing a hydrophobic decyl chain. This step both reduced the pore size and hydrophilicity of the pore surface, however, could be reversed by cleaving the imine at low pH in an ethanol/water mixture.

Dynamic control of the pore properties was demonstrated using the catalytic reduction of p-nitrophenol in aqueous conditions by gold nanoparticles, which were imbedded into both amine and imine/decyl SBA-15 materials. The more porous/hydrophilic amine-based material completely reduced p-nitrophenol to p-aminophenol after 30 minutes, whereas the more hydrophobic imine-based surface exhibited no catalytic activity. The authors suggest that this methodology could be used to generate a host of new covalently functionalised materials with tuneable surface properties.

Reversible control of pore size and surface chemistry of mesoporous silica through dynamic covalent chemistry: philicity mediated catalysis
Dheeraj Kumar Singh, B. V. V. S. Pavan Kumar and M. Eswaramoorthy
Nanoscale, 2015, Advance Article. DOI: 10.1039/C5NR02959G

Dr Mike Barrow is a guest web writer for the Nanoscale blog. He currently works as a Postdoctoral Researcher at the University of Liverpool.

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A SERS biosensor for detecting metal ions in saliva

A gold nanohole array based surface-enhanced Raman scattering biosensor for detection of silver(I) and mercury(II) in human saliva

Researchers from West Virginia University have developed a method for detecting heavy metal ions in human saliva. Silver (I) (Ag) and mercury (II) (Hg) ions form part of dental fillings so it is important to have non-invasive analytical methods to monitor the toxicity of these metal ions should they be accidentally released into saliva.

Here, the authors exploited the strong electromagnetic coupling between gold (Au) nanostars and a Au nanohole array to detect Ag (I) and Hg (II) using surface enhanced Raman scattering (SERS). The Au nanostars and nanohole array were functionalised with mismatched pairs of single-stranded (ssDNA) probes that hybridise to form stable duplexes in the presence of the corresponding metal ions. Hybridisation allows the Au nanostars to come into close proximity with the Au nanohole array, which results in a large amplification of the SERS signal.

In this way, the authors were able to detect Ag (I) and Hg (II) ions in human saliva with limits of detection (LODs) of 0.17 nM and 2.3 pM for Ag (I) and Hg (II), respectively. This demonstrates the applicability of the SERS-based detection platform for on-site, non-invasive detection of analytes in body fluids.

A gold nanohole array based surface-enhanced Raman scattering biosensor for detection of silver(I) and mercury(II) in human saliva
Peng Zheng, Ming Li, Richard Jurevic, Scott K. Cushing, Yuxin Liu and Nianqiang Wu
Nanoscale, 2015, 7, 11005-11012. DOI: 10.1039/C5NR02142A

Dr Lee Barrett is a guest web writer for the Nanoscale blog. Lee is currently a postdoctoral researcher in the Centre for Molecular Nanometrology at the University of Strathclyde. His research is currently focused on the development of nanoparticle-based sensors and surface enhanced Raman scattering (SERS). Follow him on twitter @L_Bargie.

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Poster prize winners at the 10th Sino-US Symposium on Nanoscale Science and Technology

Many congratulations to Chuanbo Gao and Mengyu Yan for winning the Nanoscale and Nanoscale Horizons poster prizes at the 10th Sino-US Symposium on Nanoscale Science and Technology.

Chuanbo, from the Xi’An Jiaotong University, and Mengyu, from Wuhan University, won prizes for their posters entitled “Etching-free epitaxial growth of gold on silver nanostructures for high chemical stability and plasmonic activity” and “Vanadium oxide/graphene nanocomposite for advanced lithium battery”, respectively.

The 10th Sino-US Symposium on Nanoscale Science and Technology took place from 26th to 28th June 2015 at Wuhan University of Technology, China. The conference is organised by the Wuhan University of Technology, University of California, Los Angeles, and Wuhan University, and aims to provide a platform for scholars, experts, research institutes, and companies to share the latest research progress in nanoscience and technology research. This year’s event was the largest symposium ever held in the history of the Forum, with over 1,000 participants. Further details are available on the conference website.

Nanoscale and Nanoscale Horizons will be awarding more prizes throughout the year – keep an eye out to find out about the winners!

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