Articles ASAP

Nanoribbons Excel as Li-ion Battery

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.

Fabrication and Electrochemical Characterization of TiO2 Three-Dimensional Nanonetwork Based on Peptide Assembly
Sung-Wook Kim, Tae Hee Han, Jongsoon Kim, Hyeokjo Gwon, Hyoung-Seok Moon, Sang-Won Kang, Sang Ouk Kim and Kisuk Kang
ACS Nano, [Online early access].
Web release date: April 27, 2009
http://dx.doi.org/10.1021/nn900062q

To Top

Nanofiber Scaffolds for Neuroregenerative Applications

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.

Neurite Outgrowth on Nanofiber Scaffolds with Different Orders, Structures, and Surface Properties
Jingwei Xie, Matthew R. MacEwan, Xiaoran Li, Shelly E. Sakiyama-Elbert and Younan Xia
ACS Nano, [Online early access].
Web release date: April 27, 2009
http://dx.doi.org/10.1021/nn900070z

To Top

Novel Nanocontainers – Nanocups, Nanorings, and Nanocup Arrays

While there has been an explosion in the types of new nanostructures being synthesized, the synthesis of short structures has proven impossible by existing techniques due to the difficulty in controlling and terminating growth during initial stages of synthesis. Yung Joon Jung and coworkers have developed a method for fabricating structures from graphitic carbon that have up to 105 times smaller length/diameter ratios compared to carbon nanotubes. These new nanoparticles show unique morphologies as nanocups, nanorings, and connected nanocup arrays. The nanocups are effectively used to hold and contain other materials leading to the formation of multicomponent hybrid nanostructures with applications in nanomedicine and nanometrology.

Engineering Low-Aspect Ratio Carbon Nanostructures: Nanocups, Nanorings, and Nanocontainers
Hyunkyung Chun, Myung Gwan Hahm, Yoshikazu Homma, Rebecca Meritz, Koji Kuramochi, Latika Menon, Lijie Ci, Pulickel M. Ajayan, and Yung Joon Jung
ACS Nano, [Online early access].
Web release date: May 1, 2009
http://dx.doi.org/10.1021/nn9001903

To Top

Drug Delivery Dependent on Nanoparticle Surface

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.

Protonated Nanoparticle Surface Governing Ligand Tethering and Cellular Targeting
Abhilash Vincent, Suresh Babu, Eric Heckert, Janet Dowding, Suzanne M. Hirst, Talgat M. Inerbaev, William T. Self, Christopher M. Reilly, Artm E. Masunov, Talat S. Rahman, and Sudipta Seal
ACS Nano, [Online early access].
Web release date: April 15, 2009
http://dx.doi.org/10.1021/nn9000148

To Top

Current Issue

Nanowire Solar Cells See the Light

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.

Enhanced Harvesting of Red Photons in Nanowire Solar Cells: Evidence of Resonance Energy Transfer
Karthik Shankar, Xinjiang Feng, and Craig A. Grimes
ACS Nano, 2009, 4, 788-794.
http://dx.doi.org/10.1021/nn900090x

To Top

Rational Design of Nanorod Biosensors

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.

Rational Selection of Gold Nanorod Geometry for Label-Free Plasmonic Biosensors
Greg J. Nusz, Adam C. Curry, Stella M. Marinakos, Adam Wax, and Ashutosh Chilkoti
ACS Nano, 2009, 4, 795-806.
http://dx.doi.org/10.1021/nn8006465

To Top

Bottom-Up Assembly of Gold Nanorod Dimers

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.

Self-Assembled Nanogaps via Seed-Mediated Growth of End-to-End Linked Gold Nanorods
Titoo Jain, Fredrik Westerlund, Erik Johnson, Kasper Moth-Poulsen, and Thomas Bjørnholm
ACS Nano, 2009, 4, 828-834.
http://dx.doi.org/10.1021/nn900066w

To Top

Nanocomposite Enhances Li-ion Battery

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

Self-Assembled TiO₂–Graphene Hybrid Nanostructures for Enhanced Li-Ion Insertion
Donghai Wang, Daiwon Choi, Juan Li, Zhenguo Yang, Zimin Nie, Rong Kou, Dehong Hu, Chongmin Wang, Laxmikant V. Saraf, Jiguang Zhang, Ilhan A. Aksay, and Jun Liu
ACS Nano, 2009, 4, 907-914.
http://dx.doi.org/10.1021/nn900150y

To Top

Towards an Implantable Glucose Sensor

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.

Size-Selective Diffusion in Nanoporous but Flexible Membranes for Glucose Sensors
Hiroki Uehara, Masaki Kakiage, Miho Sekiya, Daisuke Sakuma, Takeshi Yamonobe, Nao Takano, Antoine Barraud, Eric Meurville, and Peter Ryser
ACS Nano, 2009, 4, 924-932
http://dx.doi.org/10.1021/nn8008728

To Top

Constructing Nanostructures via Orthogonal Reactivity

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.

Orthogonal Reactivity of Metal and Multimetal Nanostructures for Selective, Stepwise, and Spatially-Controlled Solid-State Modification
Brian M. Leonard, Mary E. Anderson, Karl D. Oyler, Ting-Hao Phan, and Raymond E. Schaak
ACS Nano, 2009, 4, 940-948
http://dx.doi.org/10.1021/nn800892a

To Top

To see a complete list of ASAP articles, click here.

Register for email alerts from ACS Nano

Copyright 2009 American Chemical Society