Hotter and hotter: increasing the potential of gold nanostars

Iain Larmour is a guest web writer for ChemSci. He has researched a wide variety of topics during his years in the lab including nanostructured surfaces for water repellency and developing nanoparticle systems for bioanalysis by surface enhanced optical spectroscopies. He currently works in science management. In his spare time he enjoys reading, photography, art and inventing.

Gold nanostars are gold nanoparticles with multiple branches, a shape which gives rise to their unique properties. These nanoparticles have tuneable localized surface plasmon resonances in the biologically transparent near-IR window, and excitation of these plasmons using a laser creates a local temperature  increase. For this reason, gold nanostars have potential for use in non-invasive antitumoral and antibiofilm laser treatments.

The problem faced by scientists, however, is how to achieve a temperature increase that is large enough to be effective, without exposing the overlying skin to a level of irradiation that exceeds the safe limits. This is what Piersandro Pallavicini from the Department of Chemistry at the University of Pavia, and an international team of colleagues, set out to investigate.

They generated gold nanostars with plasmon resonances at 835 and 1530 nm, respectively. Each of these plasmons could be irradiated separately, leading to observable increases in temperature. However, when both plasmons were irradiated simultaneously, the temperature increase was equal to the sum of the temperature increases when the plasmons were irradiated separately.

Temperature increases observed from the laser excitation of individual or multiple plasmon resonances of gold nanostars

The implication of these findings is that Pallavicini and colleagues successfully found a way to obtain a larger local temperature increase using irradiation that remains below the safe limits. This significantly increases the potential of gold nanostars for application in the in the treatment of biofilm growth on implants in vivo.

To find out the full details of the additive temperature effect, read the ChemComm article today – it’s free to access until 21st October 2015:

Monolayers of gold nanostars with two near-IR LSPRs capable of additive photothermal response
Piersandro Pallavicini, Simone Basile, Giuseppe Chirico, Giacomo Dacarro, Laura D’Alfonso, Alice Dona, Maddalena Patrini, Andrea Falqui, Laura Sironi and Angelo Taglietti
Chem. Commun., 2015, 51, 12928-12930
DOI: 10.1039/C5CC04144A

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Connecting electrodes with light illuminates electrochemistry

Danielle Whittaker writes about a hot Chemical Science article for Chemistry World

Scientists in Australia have lit the path towards replacing wires in electrochemical devices by using visible light to create electrical currents on a stabilised silicon semiconductor electrode.

Electrodes in conventional devices must be connected to an external electrical circuit, often requiring a mesh of wires and bonding pads to produce an array of independently controlled electrodes. These components take up a vast amount of space on electronic chips, limiting the electrode density. Read the full article in Chemistry World»


You can read the original journal article in Chemical Science:
Connecting electrodes with light: one wire, many electrodes
Moinul H. Choudhury, Simone Ciampi, Ying Yang, Roya Tavallaie, Ying Zhu, Leila Zarei, Vinicius R. Gonçales and J. Justin Gooding
DOI: 10.1039/C5SC03011K, Edge Article

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Announcing the ChemComm Emerging Investigator Issue 2016

We are delighted to announce the forthcoming 2016 ChemComm Emerging Investigators issue. This special issue, now in its sixth year, will showcase the high quality research being carried out by international researchers in the early stages of their independent careers.

If you are interested in submitting to the issue please contact the ChemComm Editorial Office in the first instance. Please note that authors must not have featured in a previous ChemComm Emerging Investigators issue. The deadline for submission is 18 January 2016.

This annual issue is dedicated to profiling the very best research from scientists in the early stages of their independent careers from across the chemical sciences. We hope to feature principal investigators whose work has the potential to influence future directions in science or result in new and exciting developments.

C5CC90126JAlso of interest:

Browse the 2015 Emerging Investigators issue

Find out more about the winners of the recent ChemComm Emerging Investigator Lectureship – awarded annually to exceptional scientists in the early stage of their independent career

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Electric switch makes helix change hands

Elisabeth Ratcliffe writes about a hot ChemComm article for Chemistry World

Electric fields can switch both the net dipole moment and the helical handedness of helical supramolecular structures, according to a theoretical study by scientists in India.

Benzene-1,3,5-tricarboxamide (BTA) molecules self-assemble, by hydrogen bonding, into columnar structures with a macrodipole moment along their stacking direction. Each BTA molecule can form three hydrogen bonds by using oxygen atoms in the amide groups and the direction of these hydrogen bonds determines the direction of the dipole moment. Read the full article in Chemistry World»

Application of an electric field in the direction opposite to that of the macrodipole reverses the handedness of the structure


You can read the original journal article in ChemComm – it’s free to download until 14 October 2015:
External electric field reverses helical handedness of a supramolecular columnar stack
Karteek K. Bejagam, Chidambar Kulkarni, Subi J. George and Sundaram Balasubramanian�
DOI: 10.1039/C5CC05569E, Communication

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ChemComm Emerging Investigator Lectureship 2015: Winners and lectures announced

On behalf of the ChemComm Editorial Board, we are delighted to announce the winners of the 2015 ChemComm Emerging Investigator Lectureship: Deanna D’Alessandro (synthetic inorganic chemistry and molecular materials), University of Sydney, Australia, and Yong Sheng Zhao (organic nanophotonic materials), Institute of Chemistry, Chinese Academy of Sciences, China. Congratulations to Deanna and Yong Sheng!

Yong Sheng Zhao

Yong Sheng Zhao

Yong Sheng kicked off his Lectureship tour at the Asian Pacific Conference on Chemistry of Materials (APCCOM) 2015 on 20 August, followed by a presentation at the 6th International Conference on Nanoscience and Technology (ChinaNANO 2015) on 04 September, both events located in Beijing. His tour will culminate at the Royal Society of Chemistry’s 2nd Asian-European Symposium on Organic Optoelectronics on 27-29 October 2015 in Edinburgh, where he will be awarded with his official Lectureship certificate.

Deanne DAlessandro

Deanna D'Alessandro

Deanna will deliver her inaugural ChemComm EMI Lecture at a symposium on Metal-Organic Frameworks: Synthesis, Properties and Applications at Pacifichem 2015 in Hawaii this December. Further details of her Lectureship tour, including additional lecture locations, will be announced in due course.

This annual lectureship recognises an emerging scientist in the early stages of their independent academic career. For information on previous winners see our website.

Also of interest: You can now read the 2015 ChemComm Emerging Investigators Issue which highlights research from outstanding up-and-coming scientists. There is a mix of Feature articles and Communications, as well as a Profile of this year’s contributors, with cool photos to spotlight our authors at work or at play – look out for the famed Faraday Loving Cup, some serious curling, the Great Wall of China, and once again, as last year, a pumpkin is involved!  You can also take a look at our previous Emerging Investigator issues in 2011, 2012, 2013, and 2014.

Yong Sheng Zhao presents his first ChemComm EMI Lecture at the APCCOM 2015 in Beijing

Soon to come: We will soon be launching our forthcoming 2016 ChemComm Emerging Investigators issue – watch this space for more details.

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Hot ChemComm articles for September

Take a look at this selection of recently published referee-recommended articles – all are free to read* until the end of September.

Solid electrolyte interphase in semi-solid flow batteries: a wolf in sheep’s clothing
E. Ventosa, G. Zampardi, C. Flox, F. La Mantia, W. Schuhmann and J. R. Morante 
DOI: 10.1039/C5CC04767F, Communication

C5CC04767F GA


A new label-free strategy for a highly efficient chemiluminescence immunoassay
Zhanjun Yang, Yue Cao, Juan Li, Juntao Wang, Dan Du, Xiaoya Hu and Yuehe Lin 
DOI: 10.1039/C5CC05337D, Communication

C5CC05337D GA


A luminescent ruthenium(II) complex for light-triggered drug release and live cell imaging
Nora Karaoun and Anna K. Renfrew 
DOI: 10.1039/C5CC05172J, Communication

C5CC05172J GA


Tuning the properties of the UiO-66 metal organic framework by Ce substitution
Farid Nouar, Matthew I. Breeze, Betiana C. Campo, Alexandre Vimont, Guillaume Clet, Marco Daturi, Thomas Devic, Richard I. Walton and Christian Serre 
DOI: 10.1039/C5CC05072C, Communication

C5CC05072C GA


Biologically inspired non-heme iron-catalysts for asymmetric epoxidation; design principles and perspectives
Olaf Cussó, Xavi Ribas and Miquel Costas 
DOI: 10.1039/C5CC05576H, Feature Article

C5CC05576H GA


Confined chromophores in tobacco mosaic virus to mimic green fluorescent protein
Quan Zhou, Fengchi Wu, Man Wu, Ye Tian and Zhongwei Niu 
DOI: 10.1039/C5CC05751E, Communication

C5CC05751E GA 

*Access is free through a registered RSC account

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Synthetic stomach membrane to minimise animal tests

Jennifer Newton writes about a hot ChemComm article for Chemistry World

The hydrogel successfully mimiced porcine gastric mucosa in mucoadhesion testing experiments

Scientists in the UK have made a synthetic surface that could replace animal tissues in liquid drug formulation tests.

‘Mucosal membranes like those in the nasal cavity, mouth, eyes, stomach, bladder and vagina are continuously being washed with biological fluids. The majority of drugs administered to these surfaces will get washed away, reducing drug absorption and efficiency of any therapy,’ explains Vitaliy Khutoryanskiy, from the University of Reading, who led the work. Read the full article in Chemistry World»


Read the original journal article in ChemComm – it’s open access:
Novel glycopolymer hydrogels as mucosa-mimetic materials to reduce animal testing
Michael T. Cook, Sarah L. Smith and Vitaliy V. Khutoryanskiy 
Chem. Commun., 2015, Advance Article
DOI: 10.1039/C5CC02428E, Communication

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Coordinating nature and photochemistry to create hydrogen

Researchers from Chicago have studied the hydrogen production possible in a ruthenium(II)–ferredoxin–cobaloxime catalytic biohybrid . Anthea Blackburn writes more.

When we look to our future energy resources, the need to realise new means of renewable energy is immediately obvious. Much research is being carried out around the world into the development of systems that can generate energy – from H2 to biofuels to solar fuels – all of which place great importance on high efficiency and sustainability.

Looking at the world around us for inspiration, the obvious candidate is the photosynthetic process, where visible light is employed to convert CO2 and H2O into chemical energy. This process involves the transport of electrons through a complex series of intricately aligned porphyrin-related and protein biomolecules. We can explore the development of a system that mimics the behaviour of natural systems, with respect to the relay of electrons along a series of molecules, or, alternatively, we can take the components in these systems and exploit their properties in combination with other electronically-active but non-natural molecules.

Upon photoexcitation of [Ru(bpy)3]2+, electron transfer through a ferredoxin scaffold to a cobaloxime catalyst facilitates the production of hydrogen.It is the latter approach which Lisa Utschig and her team from Argonne National Laboratory, near Chicago in the US, employed to generate a molecular system capable of photocatalysing the production of hydrogen. In their biohybrid system, the photosensitiser ruthenium(II) tris(bipyridine), ferredoxin (a water-soluble electron transfer protein), and cobaloxime (a cobalt(II)-based catalyst), were combined to generate a miniature reaction center that mimics those which occur in biological systems. However, the Utschig group’s system has a smaller molecular weight, which allows for characterisation of the electronic processes that occur in the system.

Lisa and her colleagues found that the presence of ferredoxin in the catalytic system acted as a scaffold to stabilise the charge-separated state necessary for electron transfer and the desired production of H2. They also observed that the catalytic behaviour of the Ru(II)–Co(II) pair was only possible in the presence of ferredoxin, which acted to extend the lifetime of the otherwise transient Co(I), allowing the desired reaction to occur.

In order to fully understand and enhance the properties of the molecular systems developed to fulfil the increasing need for energy alternatives, we need to be able to probe the structure and processes that occur in the molecule; the use of smaller analogs to those that exist in nature offers a means by which to achieve this goal. The photoactivated catalyst discussed in this work is an important step forward in the development of an optimized system for use in solar fuel production.

Read this hot ChemComm article in full:
Aqueous light driven hydrogen production by a Ru–ferredoxin–Co biohybrid
S. R. Soltau, J. Niklas, P. D. Dahlberg, O. G. Poluektov, D. M. Tiede, K. L. Lulfort and L. M. Utschig
Chem. Commun., 2015, 51, 10628–10631
DOI: 10.1039/C5CC03006D

Biography

Anthea Blackburn is a guest web writer for Chemical Science. She hails originally from New Zealand, and is a recent graduate student of Northwestern University in the US, where she studied under the tutelage of Prof. Fraser Stoddart (a Scot. There, she exploited supramolecular chemistry to develop multidimensional systems and study the emergent properties that arise in these superstructures. When time and money allow, she is ambitiously attempting to visit all 50 US states.

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How could a tree make tramadol?

Andrea McGhee writes about a hot ChemComm article for Chemistry World

Researchers in France, Switzerland and Cameroon are convinced that the African pin-cushion tree produces the well-known painkiller Tramadol and are determined to prove it. Back in 2013, a team led by neuroscientist Michel de Waard, of the Joseph Fourier University, claimed that significant quantities of the drug were present in the root bark extract of Nauclea latifolia, which has long been used by locals in West and Central Africa to treat pain and disease.

Last year another team, led by Michael Spiteller who is based at the Technical University of Dortmund, Germany, ran some tests of their own and cast doubt on these findings. Read the full article in Chemistry World»

N. latifol grows widely in Cameroon and is used by traditional healers to treat a wide variety of complaints. Image courtesy of Scott Zona / Wikipedia Commons (CC BY 2.0)


 

Read the original journal article in ChemComm – it’s free to read until 7th October:
Biomimetic synthesis of Tramadol
Florine Lecerf-Schmidt, Romain Haudecoeur, Basile Peres, Marcos Marçal Ferreira Queiroz, Laurence Marcourt, Soura Challal, Emerson Ferreira Queiroz, Germain Sotoing Taiwe, Thierry Lomberget, Marc Le Borgne, Jean-Luc Wolfender, Michel De Waard, Richard J. Robins and Ahcène Boumendjel 
DOI: 10.1039/C5CC05948H, Communication

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Molecular Sierpinski triangles get stability upgrade

Jennifer Newton writes about a hot ChemComm article for Chemistry World

Metal–nitrile coordination bonds hold the structures together

Earlier this year we reported that scientists in China had built molecular Sierpiński triangles from small aromatic building blocks. Now, another team in China has constructed fractal triangles on the molecular scale and this time, they’re much more robust. Read more in Chemistry World»

You can read the original journal article in ChemComm – it’s free to access until 28th September:
On-surface construction of a metal–organic Sierpiński triangle
Qiang Sun, Liangliang Cai, Honghong Ma, Chunxue Yuan and Wei Xu 
Chem. Commun., 2015, Advance Article
DOI: 10.1039/C5CC05554G, Communication

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