Our research centers on the development of new chemistry, physics, and technological applications of nanomaterials -- a novel class of  materials with feature size <100 nm. New technologies will emerge from these materials that can improve the way we live just as microtechnology has done over the past several decades.

1. Understanding and Control of Nanomaterial Synthesis

This research focuses on a long-standing problem in chemistry and physics -- understanding and control of the nucleation/growth steps involved in the chemical synthesis of nanomaterials. We aim to bring revolutionary advances to this field  by developing new tools capable of capturing, identifying, and quantifying the clusters that serve as a bridge between atomic species and nanostructures. This research requires the integration of chemical synthesis, theoretical modeling, cluster speciation using mass spectrometry and electron microscopic analysis. It will provide an atomistic picture of the evolution pathway from atoms to clusters and nanostructures, as well as the design rules for synthesizing metal and semiconductor nanomaterials with well-controlled electronic, magnetic, catalytic and optical properties. The ultimate goal of this work is to build a scientific base for large-scale production of nanomaterials with the specific properties sought for applications in areas such as electronics, photonics, catalysis, information storage, optical sensing, biomedical research.

2. Colloidal Self-Assembly and Photonic Crystals

This research explores the use of self-assembly to fabricate photonic crystals where monodispersed spherical colloids (50 nm to 1 um in size) serve as building blocks. We aim to demonstrate the fabrication of active photonic crystals whose band gaps can be reconfigured with an external magnetic field. This research requires the development of chemistry for synthesizing a novel class of colloidal building blocks that have spherical shape but non-spherical symmetry. It will provide a conceptually new approach to fabrication of active photonic crystals that can be exploited to fabricate optical switches with fast response times; light-emitting-diodes with coherent outputs; and diode lasers with low thresholds. These new materials also hold the key to the continuous progress toward all-optical, integrated circuits that will play a critical role in future communication and computing systems.

3. Biomedical Applications of Nanomaterials

Because of their small sizes and superb properties, nanomaterials are finding widespread use in studying complex biological systems. As the newest effort, we are exploring the use of gold nanocages (nanoboxes with porous walls) as SERS substrates for biosensing, as contrast enhancement agents for optical imaging, as therapeutic agents for photothermal treatment, and as carriers for drug delivery. We are applying electrospun nanofibers to drug delivery and tissue engineering. We are also developing superparamagnetic colloids for the separation, manipulation, and detection of biological species and events. In the near future, nanomedicine should become the focus of the entire research group.