- Surface and Polymer Chemistry

We utilize various approaches to derivatize, modify, conjugate, enhance, and/or passivate surfaces, biomolecules, microbeads, and nanoparticles. Examples of this can be seen in our microbead arrays, in which a glass coverslip derivatized with biotin moieties is used to capture a streptavidin-coated microbead conjugated to DNA molecules. This type of platform can support a wide variety of applications such as DNA sequencing, genotyping, and DNA-protein interaction studies. The surface chemistry plays a crucial role in our detection schemes by minimizing non-specific binding and thus increasing sensitivity. We are also interested in the synthesis and fabrication of brush polymer arrays on planar surfaces. Each array feature serves as a micro/nano reactors for DNA amplification, highly multiplexed measurements of molecular interactions, such as DNA-transcription factor binding.

- Synthetic Chemistry

We design and synthesize (by both liquid and solid-phase organic synthesis) photocleavable and chemically cleavable nucleotides for DNA sequencing applications, and surface chemistry. We also explore new approaches by combining the best of bottom-up (by chemical synthesis) and top-down (by nanofabrication and macromolecular engineering) methods. Templated organic synthesis methodologies are used to engineer molecular and nano devices on larger biomolecular or solid-state nano scaffolds.

- Physical and Analytical Chemistry

We develop new optical methods and fluidic devices for measuring the kinetics of enzymatic reactions. We are also interested in developing methods and instruments for: 1) DNA shearing or fragmentation by hydrodynamic shear flow; 2) single-cell sorting, selection and capture; 3) quantitative transport, fractionation and recovery of biomolecules from single cells or any small-volume biological samples; 4) on-chip direct analysis of DNA, RNA and protein molecules by either single optical imaging/sequencing or electronic measurements;