The overarching theme of our research is to utilize the powerful biomolecular approach to manipulate nanomaterials for applications. Our current research projects are listed below.
SEPARATION OF PURE-CHIRALITY CARBON NANOTUBES
Our research focuses on the separation of pure-chirality single-wall carbon nanotubes (SWCNTs) from as-synthesized material in a polymer aqueous two-phase system with precise pH control using recognition DNA sequences. The atomic structure of each SWCNT species corresponds to a unique pair of integers (n, m) with well-defined structure and property. SWCNTs can be metals, quasi-metals, and semiconductors and have defined handedness, therefore applications of SWCNTs depend on the distinct properties of (n, m) species. We have primarily focused on the fundamental understanding of mechanisms of optical modulation and separation outcome of DNA-wrapped SWCNTs through precise pH control of a polymer aqueous two-phase system.
BIO-NANO HYBRID MATERIALS AS FLUORESCENT PROBES
Semiconducting, pure-chirality SWCNTs emit light in the near-infrared region, a spectral regime that is important to the development of high contrast fluorescence detection in complicated biological samples. The surface engineering of SWCNTs with biomolecules such as DNA and biomimetic glycopolymers creates versatile nanomaterial-based probes to detect specific molecular interactions in biological processes with enhanced sensitivity and selectivity. We are currently focusing on nanotube chemistry using pure-chirality SWCNTs and biomimetic, precision synthesized glycopolymers that closely mimic the natural glycan structures and functions. These hybrids have precise optical and carbohydrate functionalities which can be utilized as multicolor fluorescent probes to profile protein-carbohydrate recognition. This can lead to clarifying functions of both molecules and their underlying molecular mechanism and discovering therapeutic and diagnostic mechanism as well. This multidisciplinary, collaborative project with faculty members at CSU includes surface functionalization and assessing the basal toxicity and functionality of nanomaterial-based probes as biocompatible, cancer-cell targeting multicolor fluorescent probes.
SELF-ASSEMBLY OF NANOMATERIALS
The liquid phase processing including dispersion, purification, and assembly of nanomaterials is important for effectively translating unique properties of individual molecules into assembled solid materials, such as films and fibers. We have produced aligned boron nitride nanotube (BNNT) films utilizing DNA as an effective dispersant. BNNTs have exceptional mechanical, thermal, and chemical properties as well as ultraviolet and neutron radiation shielding capabilities. We are focusing on understanding the dispersion behavior of DNA-stabilized BNNTs depending on solvents used and the concentration and polydispersity of nanotubes and linking the dispersion behavior to final properties of assemble materials. We are also exploring multifunctional applications of BNNTs such as aligned films and fibers for high-performance thermal management material and lightweight, strong protective shielding for electronic and optoelectronic devices and aerospace applications.