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nanotimes News in Brief

Silver nanoparticles cause more damage to testicular cells than titanium dioxide nanoparti- cles, according to a recent study by the Norwegian Institute of Public Health.The researchers found that silver nanoparticles had a toxic effect on cells, suppressing cellular growth and multiplication and causing cell death depending on concentrations and duration of exposure. The effect was weaker for titanium dioxide nanoparticles, although both types did cause cell type-specific DNA damage, with pos- sible implications on reproduction as well as human and environmental health.

“It seems that the type of nanoparticle, and not the size alone, may be the limiting factor,” says Nana Asare, primary author of the study.

Nana Asare, Christine Instanes, Wiggo J. Sandberg, Ma- gne Refsnes, Per Schwarze, Marcin Kruszewski, Gunnar Brunborg: Cytotoxic and genotoxic effects of silver nano- particles in testicular cells, In: Toxicology, Vol. 291(2012), Issues 1-3, January 27, 2012,Pages 65-72, DOI:10.1016/j. tox.2011.10.022:

http://dx.doi.org/10.1016/j.tox.2011.10.022 © Image on page 2: Fraunhofer IKTS, Dresden

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boron nitride or molybdenum disulfide acting as a vertical transport barrier. © Science

L. Britnell, R. V. Gorbachev, R. Jalil, B. D. Belle, F. Sche- din, A. Mishchenko, T. Georgiou, M. I. Katsnelson, L. Ea- ves, S. V. Morozov, N. M. R. Peres, J. Leist, A. K. Geim, K. S. Novoselov, L. A. Ponomarenko: Field-Effect Tunneling Transistor Based on Vertical Graphene Heterostructures, In: Science Expess, February 2, 2012, DOI: 10.1126/sci- ence.1218461:

http://dx.doi.org/10.1126/science.1218461

Scientists at Johannes Gutenberg University Mainz (JGU) in Germany have developed a new method of observing individual proteins. The new method is based on the use of gold nanoparticles.

“Our method allows live tracking of individual proteins without having to label them first,” ex- plains Professor Dr. Carsten Soennichsen of the Institute of Physical Chemistry at JGU. “We are now gaining entirely new insights into molecular processes and can see, for example, how things are constantly in motion even on the very smallest scale.”

Researcher at University of Manchester (UK), Radboud University of Nijmegen (NL), University of Nottingham (UK), Institute for Microelectro- nics Technology (RU), Universidade do Minho (PL), and Momentive Performance Materials (US) report a bipolar field-effect transistor that exploits the low density of states in graphene and its one atomic layer thickness. Their prototype devices are graphene heterostructures with atomically thin

Irene Ament, Janak Prasad, Andreas Henkel, Sebastian Schmachtel & Carsten Sönnichsen: Single unlabeled pro- tein detection on individual plasmonic nanoparticles, In: Nano Letters, Vol. 12, Issue 2, February 8, 2012, Pages 1092-1095, DOI:10.1021/nl204496g: http://dx.doi.org/10.1021/nl204496g