Past Seed Projects and Clusters

2007 Seed Projects

Self-Assembled Nanoscale Matrices for DNA Electrophoresis

PIs: Kevin Dorfman, Eray Aydil

In this project, we propose to use self-assembled, nanoscale artificial gels in a microfluidic channel to separate long DNA. Fabricating this system will be commensurate with the difficulty in preparing a polyacrylamide gel, a standard method in molecular biology. However, due to the ability to control the order and density of the self-assembled system through kinetic and thermodynamic factors, we will be able to tune the device for separating a particular size range of DNA, reduce dispersion during the separation, and increase the reproducibility. The availability of such a system will greatly accelerate biological research. Based on a nominal separation time of 1 min, the throughput of our device is over 1000 times higher than PFGE, while concomitantly greatly reducing the amount of DNA required per analysis. The devices will be disposable, a major advance over existing nanolithographic devices. read more

Magnetic Iron Oxide Nanoparticles for Biomedical Applications:
Particle Synthesis, Surface Functionalization and Tissue Uptake

PIs: Steven L. Girshick, John C. Bischof

Magnetic iron oxide nanoparticles are currently the subject of intense study for medical applications. Magnetic nanoparticles show promise as contrast-enhancing agents for cancer detection using magnetic resonance imaging, as miniaturized heaters capable of killing malignant cells by application of an external field, and as targeted drug delivery vehicles. Girshick proposes a novel thermal plasma process to synthesize size-controlled magnetic iron oxide nanoparticles, passivated with an SiO₂ layer produced by photoinduced chemical vapor deposition [ref]. As these magnetic particles are aimed at imaging and therapeutic applications, Bischof will attach polyethylene glycol (PEG) and targeting ligands to the particles, as illustrated in Fig. X, and will study their in vivo uptake within tissue by MRI. Key issues include control of particle size and coating thickness, and understanding the mechanisms of both tissue uptake and the resulting spatial distribution. read more

Fabrication and Application of Topographically Tunable Metal Nanostructures

PIs: Christy L. Haynes

In this work, patterning techniques and layer-by-layer polyelectrolyte deposition will be used to produce surface-confined nanoparticles of arbitrary structure in high yield. Thus far, it has been difficult to prepare nanoparticles with the correct surface charge and stability so that dispersion into polymer layering materials is possible. In situ generation of nanoparticles after multilayer film formation will overcome this challenge. Incubation of the resulting nanoparticle/polymer composite structure in an electroless plating solution will yield fully coated metallic nanostructures, arranged based on the prescribed spatial relationships. The resultant structures will be used to study the fundamental interactions underlying plasmonic devices and surface-enhanced spectroscopies, when noble metal plating is used, as well as a range of other size-dependent phenomena, with the deposition of other materials. read more

Structural and Optical Properties of Silicon Nanoparticles:
Can Small Shape Changes Affect the Optic Response?

PIs: Traian Dumitrica

Much of the success in building electronic devices stems from our ability to control in bulk Si the electronic states around the last occupied first empty levels. This has stimulated efforts in controlling the electronic states around the gap in Si quantum dots (QDs). Most of the previous theoretical works focused on the possibility to control these levels by doping with impurities but in practice doping at the nanoscale is extremely difficult. For this reason this Seed explores a new possibility, namely to control the electronic states by modifying the quantum confinement through QD shape changes, such as aspect ratio changes caused by an applied external strain. Depending on the core structure and the arrangement of facets, QDs can have different symmetries. Results [1] from our previous Seed showed that the QD symmetry is an additional important player and thus will be considered. For example, in highly symmetric QDs, we see that even small shape changes can dramatically affect the optic response read more

Robust Solid-Contact Reference Electrodes for Electrochemical Sensors:
Merging Advantages of Ionic Liquids and Nanoporous Carbon Contacts

PIs: Philippe Buhlmann, Andreas Stein

Solid-contacted ion-selective electrodes (ISEs) with three-dimensionally ordered macroporous (3DOM) carbon as a layer between an ionophore-doped polymeric membrane and a metal contact were shown by the groups of Buhlmann and Stein to provide unprecedented long-term stability (1,2). These results put them now in an ideal position to challenge one of the biggest problems in the field of electrochemical sensors, i.e., the development of miniaturizable reference electrodes with long-term stability. Receptor-based ISEs are used for over a billion analyses per year in clinical diagnostics, process control, and environmental monitoring. With a view to mass fabrication and measurements in small volumes, the miniaturization of these sensors is very desirable, but represents an unsolved problem. read more

2006 Seed Projects

New Routes to Biorenewable Plastics: Converting Natural Resources to Environmentally Friendly Materials

• William Tolman
• Marc Hillmyer
• Thomas Hoye

Monodispersed Zinc Oxide Nanoparticle-Dye Dyads and Triads: Characterization of the Early events in Dye Sensitized Solar Cells

• Wayne Gladfelter
• Kent Mann
• David Blank

Modeling of Dye Sensitized Solar Cells

• Jeffrey Derby
• Eray Aydil

Zeolite Growth in Confined Spaces

• Lee Penn
• Michael Tsapatsis
• Andreas Stein
• Alon McCormick

High Speed Characterization Methods for Polymer Substrates

• Rhonda Drayton

Molecular Engineering of Photo-Responsive Bioactive Surfaces

• Wei Shen