Chemistry
and Materials Science
Alexander D. Li
Folded or Self-Assembled Molecular Systems
Molecular
recognition followed by nano-actuation to accomplish
a specific task is ubiquitously used in biological machinery.
Most research to date has been focused on building an “harmonic” interface
between soft biomolecules and hard man-made materials;
whereas our research focuses on integrating smart biological
functionality with desired physical properties into a
single foldable hybrid macromolecule. Of particular importance
is that such hybrid macromolecules are complete packages
with necessary properties, including molecular recognition
and nano-actuation that trigger a sensitive optical absorption
or fluorescent emission change. Applications of these “smart” polymers
as biosensors and molecular machinery should have tremendous
impact in the fields of genomics, diagnosis of infectious
disease, and biological Threat Reduction (TR) and therefore
help solve a great variety of problems in health, environment,
and national security.
 |
Figure
1. Photograph of photoluminescence from
monomer and folded oligomers at various concentrations. |
Using
such “smart” hybrid polymers, we have demonstrated
that it is possible to detect the presence of target
DNA molecules or regulatory proteins, or even a single
nick in a double stranded DNA. Current detection platforms
are based on changes of photoluminescence color. In collaboration
with Dr. Ray Reeves at the School of Molecular Bioscience,
we are exploring innovative ways to apply foldable polymers
for identifying high-mobility-group protein biomarkers
of many types of cancers. Recently, we have demonstrated
that protein binding induces a distinct color change
in the foldable polymer under laboratory-controlled conditions.
Our long-term objectives are to use these foldable macromolecules
to probe regulatory events in vivo and to further our
understanding of abnormal cell transformations underlying
molecular mechanisms of disease. Furthermore, we are
interested in applying foldable hybrid polymers in the
detection of biological threat agents through binding
of specific target sites or signature biomolecules (DNA
or proteins).
Current
research programs in Dr. Li’s lab focus on:
- Biosensors
(DNA and DNA damage, regulatory proteins)
- Thermophilic
foldable polymers
- Self-organized
nanostructures
- Macromolecular
self-assemblies and nanoparticles
- Advanced
photonic materials and molecular machinery
- Synthetic
and biological hybrid polymers
| Figure
2. A thermophilic pentamer has a chromophoric
core surrounded by DNA hairpin structures. Recognition
to target DNA triggers unfolding and induces dramatic
color changes. |
 |
Contact
Information
Alexander D. Li, Ph.D.
Associate Professor
Department of
Chemistry
Washington State University
PO Box 644630
Pullman, WA 99164-4630
Telephone:
509-335-7196
E-mail: dequan@wsu.edu
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