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nanotimes News in Brief

Stimulated Near-Infrared Light Emission in Gra- phene: The electronic properties of graphene allow a population inversion to be established within the duration of a 35-femtosecond light pulse. A view- point by Ilias E. Perakis, Department of Physics, University of Crete and Institute of Electronic Structure & Laser, Foundation for Research and Technology-Hellas, Greece.

Ilias E. Perakis: Viewpoint: Stimulated Near-Infrared Light Emission in Graphene, In: Physics, Vol. 5, No. 43, April 16, 2012, DOI:10.1103/Physics.5.43: http://physics.aps.org/articles/v5/43

12-04 :: April/May 2012

care products. The next step is to extend its use in a wide range of biomedical and consumer products. This is an alternative solution which could replace antibiotics – currently the main defence against bacteria – now powerless against super bugs. The coating is made from Dimethyldecylammonium Chitosan methacrylate.

This “sponge-like” polymer holds a positive charge, which acts as a magnet-type of force to draw in bacteria which has a negative charge on their cell walls. When the bacterium comes in contact with the coating, the cell walls are ‘sucked’ into the na- nopores, causing the cell to rupture, thus killing the bacterium.

“The coating can also be applied on biomedical objects, such as catheters and implants to pre- vent bacterial infections, which is a serious cause of concern as many bacteria are now developing resistance to antibiotics - currently our main source of treatment for infections,” lead researcher Prof. Chan said.

Image: Nanoporous antimicrobial coated contact lenses and antimicrobial solution. © NTU

Conceived at Nanyang Technological University (NTU), it comes in the form of a coating which has a magnetic-like feature that attracts bacteria and kills them without the need for antibiotics. The killer coating, which has shown to destroy 99 per cent of the bacteria and fungi that it comes in contact with, is now being used by two companies: a contact lens manufacturer and a company specialising in animal

Peng Li, Chuncai Zhou, Shahrzad Rayatpisheh, Kai Ye, Yin Fun Poon, Paula T. Hammond, Hongwei Duan and Mary B. Chan-Park: Cationic Peptidopolysaccharides Show Excellent Broad-Spectrum Antimicrobial Activities and High Selectivity, In: Advanced Materials Early View, March 21, 2012, DOI:10.1002/adma.201104186: http://dx.doi.org/10.1002/adma.201104186