Ph.D., Columbia University , 2000
Our research is focused on the following three themes:
1. Chemical synthesis and photophysics of quantum materials: Quantum-size semiconductor building blocks, such as quantum dots, quantum wires, and quantum sheets and the corresponding hetero-structures have broad applications ranging from light emitting diodes, nanolasers, nanoelectronics, solar cell devices to biological fluorescent labels. Constructing highly tunable building blocks and the corresponding hetero-structures with control over the size, shape, composition, crystalinity, and their hierarchical structures is vitally important to fully exploit these materials. We aim to develop state of the art colloidal chemistry strategy to synthesize and characterize a series of novel quantum materials with unique optical and electronic properties and investigate their applications in functional nanodevices.
2. Physical chemistry of DNA nanotechnology: DNA nanotechnology allows the design and construction of nanoscale objects that have finely-tuned dimensions, orientation, and structure with remarkable ease and convenience. With the increasing complexity of the DNA nanostructural system these days, much fundamental studies are needed to further understand the underlying physical chemistry. First, we aim to systematically investigate the thermodynamics and kinetics of DNA nanostructure formation. These thermodynamics and kinetics studies will shed light on the stability of the DNA nanostructures, push the limit on their application conditions, and improve their performance. Second, we aim to engineer synthetic DNA nanostructures to model or mimic a variety of other molecules and systems. For example, synthetic DNA nanostructures can be designed to serve as models to study the binding behavior of multi-valent molecules and gain insight into how small changes to the ligand/receptor scaffolds, such as conformational flexibility or relative distance or orientation of the multiple ligands, will affect their association equilibrium with the target molecules. This is important in understanding many multi-valent interactions in nature, like pathogen invasion, immunology recognition, cell-cell interaction.
3. DNA directed deterministic positioning of nanophotonic elements: Systematical study of photonic elements interactions with deterministic positioning at nanometer scale is very important for: a) fundamental understanding of the underlying distance dependent interactions and energy transfer between various photonic elements; b) providing useful models to understand photonic antenna systems existing in nature; c) providing crucial information for constructing artificial biophotonic systems for applications ranging from light harvesting to biosensing. Along this line, we aim to use DNA directed self-assembly to: a) study distance dependent effects between metallic nanoparticles and organic fluorophores; b) construct molecular antenna systems for efficient light harvesting; c) construct and understand geometry dependent energy transfers between fluorophores. We are also collaborating with theory group to fully understand these nanostructured photonic systems. Experiments are designed to test theoretical hypothesis and modeling. New models will be developed by taking into account of many experimental parameters resulting from the deterministic positioning of photonic elements.
Yan Liu received B.S. (1993) from Shandong University Department of Applied Chemistry, specialized in Colloidal Chemistry. Her Ph.D. (2000) work in Columbia University was focused on using second harmonic generation to study the surface properties of colloidal particles. She did postdoctoral research in Rockefeller University and Duke University on studying photobiology and photochemistry of proteins and pigment. She joined the faculty of Arizona State University at Biodesign Institute in 2004. She is currently an Associate Professor in the School of Molecular Science and the Biodesign Institute at ASU. Her current research interests focus on understanding the physical chemistry aspects of DNA based self-assembly and developing applications of DNA-directed assembly in nanophotonics and nanomedicine.