The quest for economical devices with faster speeds, lighter weights, and higher feature density drives demand for new fabrication tools that create ever more complex patterns, with sub-micron features. Typical state-of-the-art fabrication is top-down and involves multiple steps and careful surface preparation; Nature, on the other hand, provides us with examples of delicate, detailed, […]
University of Pennsylvania Highlights
June 12, 2008
Carbon Nanotube Biosensors [Education]
Infection by adenovirus is initiated when Knobs (globular protein domains) on the virus periphery bind to a CAR (Coxsackie-Adenovirus Receptor) membrane protein of the host cell. Experiments [Nano Letters 7: 3086-91(2007)] showed that CAR-Knob binding can be detected with single wall carbon nanotube (SWCN) field effect transistors covalently functionalized with CAR. Molecular dynamics […]
October 10, 2007
Catalytic Protein Bundles [Research]
Penn MRSEC researchers, DeGrado, Klein, Saven and Wand are studying bundles of helical proteins (Top Figure: Typical 4-helix bundle with selected amino acid side chains E=Asp and H=His, highlighted in green –red and green-blue, respectively) that can bind metal atoms (Bottom Figure: Typical catalytic site with bound Zinc atoms - magenta) and perform the […]
October 10, 2007
Brownian Motion of an Ellipsoid [Research]
Brownian motion, the tiny random movements of small objects suspended in a fluid, has served as a paradigm for concepts of randomness ranging from noise in light detectors to fluctuations in the stock market. Penn MRSEC researchers, Yodh, Lubensky and their collaborators, have used digital video microscopy to reveal for the first time the twisty […]
October 3, 2006
De Novo Designed Proteins [Research]
Bohdana Discher
Highly simplified de novo designed proteins, maquettes, offer new opportunities for the design of catalytic or photochemically active, electrochemically regulated, bioinspired nanomaterials. To achieve efficient charge separation for energy generation and storage, we have extended work done with overall hydrophilic (HP) a-helical bundles and developed a new amphiphilic (AP) maquette family that assembles within […]
October 3, 2006
Natural Pore-Forming Proteins [Research]
Paul A. Heiney and Virgil Percec
Natural pore-forming proteins and their remodeled structures exhibit a diversity of biological and biologically inspired functions such as transmembrane channels, viral helical coats, reversible encapsulation, stochastic sensing, and pathogenic and antibiotic activity. Attempts to study synthetic porous protein mimics have been limited by the difficulty of forming periodically ordered structures […]