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I. Mechanistic Understanding of Nanocrystal Growth
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A critical step toward the utilization of particles as the building blocks
in nanotechnology is the synthesis of well-defined (size and shape)
semiconductor nanocrystals with high quantum yield emission as well as
magnetic nanocrystals with high coercivity. This step would greatly
benefit from a systematic study of nucleation and growth of inorganic
nanocrystals. Research in our group focuses on developing synthetic
methods for making narrow band-gap III-V and IV-VI semiconductor
nanocrystals. These nanocrystals can emit in the near-IR spectral
regime, which is of particular importance for biological labeling.
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II. Anisotropically Surface-Functionalized Nanocrystals
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Proteins, the biological analogs of nanocrystals, are able
to spontaneously assemble into various complicated large
structures. These structures possess well-defined sizes and shapes
based on the surface domains present on the individual protein
monomers. The key feature of proteins, allowing them to achieve such
self-assembling, is that there are generally two or more recognition
sites located at geometrically specific positions on their
surfaces. Herein, we borrow this strategy from nature and use it to
control the assembly of nanocrystals. In this project, we aim to
develop a strategy for the synthesis of anisotropically functionalized
nanocrystals. Like their biological analogs, the resulting particles
are expected to generate a wide range of architectural morphologies in a
self-assembly fashion (e.g., lamellar phases, spherical and rod-like
micelles).
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III. Multi-functional Nanocomposites for Use as Biological Markers
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Nanocrystals have demonstrated their potential to replace
molecular fluorophore probe technology in the field of biological
labeling and imaging. However, current nanocrystal markers have the
drawbacks of slow recognition kinetics and high non-specific
binding. To solve these problems, a combinatorial approach is
proposed here to fabricate multi-functional nanocomposites for use as
biological markers. These nanocomposites can be polymer spheres
encapsulating two different kinds of nanocrystals (e.g., magnetic and
fluorescent). After surface chemistry modification, these composite
polymer spheres will then be developed as highly sensitive,
target-selective, and controllable biological markers for both in vitro
and in vivo assays.
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1.
“Controlling Anisotropic Nanoparticle Growth through Plasmon Excitation”,
Jin, R.; Cao Y. C.; Hao, E.; Mtraux, G. S.; Schatz, G. C.; Mirkin, C. A.
Nature, 2003, 425, 478.
2. “Nanoparticles with Raman Spectroscopic Fingerprints for DNA and RNA
Detection”, Cao, Y.C.; Jin, R.; Mirkin, C.A. Science 2002,
297, 1536.
3. “Photoinduced Conversion of Silver Nanospheres to Nanoprisms”, Jin,
R.; Cao, Y.; Mirkin, C.A.; Kelly, K.L.; Schatz, G.C.; Zheng, J.G.
Science 2001, 294, 1901.
4. “Growth and Properties of Semiconductor Core/Shell Nanocrystals
with InAs Cores”, Cao, Y.; Banin, U. J. Am. Chem. Soc. 2000,
122, 9692.
5. "Identification of Atomic-like Electronic States in Indium
Arsenide Nanocrystal Quantum Dots", Banin, U.; Cao, Y.; Katz, D.;
Millo, O. Nature 1999, 400, 542.
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