ACS Nano: Latest Highlights (ACS Publications)

Nanoribbons Excel as Li-ion Battery

Mon, 27 Apr 2009 14:24:42 GMT

Rechargable batteries have become increasingly important to today's society and there is great interest in improving their design and function. The unique properties of nanosized materials frequently overcome the limitations of conventional bulk materials. In a recent report, Kisuk Kang and coworkers have described the synthesis and characterization of a three-dimensional network of TiO2 hollow ribbons. These novel structures are promising as rechargeable Li batteries. The nanoribbon network ensures effective transport of electrons and could have implications in the many technologies that use Li ion batteries, including renewable energy storage and electric or hybrid vehicles.

Nanofiber Scaffolds for Neuroregenerative Applications

Mon, 27 Apr 2009 14:24:42 GMT

Nervous system injuries affect thousands of people each year. As a result, there is intense interest in nerve regeneration and repair. A current paper by the research group of Younan Xia, uses electrospun nanofibers as scaffolds to culture primary dorsal root ganglia (also known as spinal nerves). The authors probe the effects of scaffold topology to understand the unique patterns of neurite outgrowth, growth cone guidance, and axonal regeneration. The results provide valuable insight into the design of new nanofiber scaffolds for neuroregenerative applications.

Novel Nanocontainers – Nanocups, Nanorings, and Nanocup Arrays

Fri, 01 May 2009 14:24:42 GMT

Drug Delivery Dependent on Nanoparticle Surface

Wed, 15 Apr 2009 14:24:42 GMT

Nanoparticles are being increasingly studied as effective drug delivery vehicles due to their small size and membrane penetration capabilities. Recently, modified nanoparticles have been designed to target specific cells but the efficiency of cellular uptake has varied. Sudipta Seal and co-workers have synthesized Transferrin-conjugated nanoparticles that specifically target lung cancer cells over healthy cells. Further, Seal's group has shown that the interaction and subsequent cellular uptake is dependent on the nanoparticle's surface and is, therefore, tunable. This is an important step in the biomedical design of effective nanoparticles drug carriers.

Nanowire Solar Cells See the Light

Fri, 20 Mar 2009 14:24:42 GMT

Solar cells have traditionally been inefficient collectors of red and near infrared light. Attempts at increasing efficiency have focused on dye-modification and dye-development. These approaches have not been successful due to a variety of reasons. In a recent report, the research group of Craig Grimes at The Pennsylvania State University has designed a dye-sensitized nanowire solar cell array that has a four-fold increase in quantum yields for red photons. The nanowire array holds the donor and acceptor molecule in place spatially without attaching them to each other. This study could lead to new designs in state-of-the-art dye-sensitized solar cells.

Rational Design of Nanorod Biosensors

Tue, 16 Mar 2009 14:24:42 GMT

Early diagnosis is vital to the successful treatment of diseases and is dependent on the detection of low concentrations of biomolecules. To this goal, scientists are intent on developing a framework to rationally design systems that are increasingly sensitive to biomolecules of interest. The research group of Ashutosh Chilkoti at Duke University has laid the foundation for such a framework. In a recent study, they have developed an analytical model that can be used for the rational design of a biosensor. Further, they discuss how the model can be utilized to guide the development of future generations of biosensors.

Bottom-Up Assembly of Gold Nanorod Dimers

Fri, 13 Mar 2009 14:24:42 GMT

Gold nanorods (AuNRs) are of interest for a wide range of applications, ranging from imaging to molecular electronics. As such, they have been studied extensively for the past decade. An important issue in AuNR applications is the ability to self-assemble the rods into predictable nanoscale structures. Recently, Erik Johnson, Thomas Bjørnholm, and co-workers have developed a novel way to assemble gold nanorod dimers through bottom-up chemical assembly. They have been able to link nanorods with a nanogap of 1-2 nm between the rods, a size that is suitable for single molecule electronics.

Nanocomposite Enhances Li-ion Battery

Thu, 26 Mar 2009 14:24:42 GMT

Batteries have become increasingly important to today's society and there is great interest in improving their design and function. In a recent report, Aksay, Liu, and coworkers have described a novel one-step method for integrating TiO2 nanoparticles with graphene sheets to form a nanocomposite that enhances the performance of Li-ion batteries. The TiO2-graphene nanocomposite outperformed pure TiO2 as an electrode additive and could have implications in the many technologies that use Li ion batteries, including renewable energy storage and electric or hybrid vehicles

Towards an Implantable Glucose Sensor

Thu, 26 Mar 2009 14:24:42 GMT

Glucose is one of the most important molecules in living animals. As such, glucose detection, separation and transport control are increasingly studied with the desire to improve some medical devices. The research groups of Uehara and Meurville have developed a flexible nanoporous membrane that is selective for glucose transport. Pore size of the membranes can be controlled from 5 to 30 nm by varying preparation conditions. In addition, the membranes show improved size selectivity of molecular diffusion and superior mechanical properties over current membrane materials. This is beneficial for downsized medical devices and can lead to an implantable glucose sensor.

Constructing Nanostructures via Orthogonal Reactivity

Thu, 26 Feb 2009 14:24:42 GMT

Orthogonal reactivity is when one component of a multi-component system reacts with a particular reagent under a specific set of conditions while the others do not, even though they are all present together in the same reaction vessel. Understanding and controlling this type of additive synthesis could lead to advances in design and construction of more complicated nanostructures. Schaak and co-workers have demonstrated that orthogonal reactivity can be used to fabricate complex nanostructures in a selective, stepwise, and spatially controlled way. This represents a powerful new strategy for creating heterogeneous nanostructures of controlled composition.