Paul Alivisatos
Lawrence Berkeley National Lab and University of California, Berkeley
Nanocrystal based macromolecular rulers
Nanocrystal solar cells
ITO
e-
h+
Al
Colloidal inorganic nanocrystals as building blocks for new materials
Symmetry, topology, connectivity…
Some SCALING LAWS for nanocrystal properties
Energy level spacing (band gap) increase ~1/r^2
Density of states, oscillator strength (~V)
Charging energy increase (~1/r)
Melting temperature reduction (~1/r)
Magnetic relaxation time (~N)
Timescale for structural metastability (~N)
Control of size and shape will be an important variable
in the design of new materials
5nm
5nm
CdSe Nanocrystal
-
Glpf Cytoplasmic surface - Glycerol in the channels
-
Conjunction of soft and hard matter
Quantum Dots as Fluorescent Biological Labels
Bruchez, M.; Moronne, M.; Gin, P.; Weiss, S.; Alivisatos, A. P., Science 1998, 281, 2013-2016.
Chan, W. C. W.; Nie, S. M., Science 1998, 281, 2016-2018.
Photostability Comparison
Alexa 488
Green QDs
Courtesy Quantum Dot Corporation
From artificial atoms to artificial molecules:
coupled inorganic nanocrystals
Plasmonic Coupling
Magnetic
coupling
Electronic Coupling
in all cases, coupling to “vibrations”
Biological analogy- macromolecular complexes
Polymer analogy -block copolymers
Alivisatos and Schultz , Nature 382 p. 609 1996; Angew. Chemie 38 p. 1808 1999
related work by (Mirkin and Letsinger,)
DNA-directed grouping of nanocrystals
P– Ph
Ph- SO3-
Ph- SO3-
Tri-phenyl phosphine sulfonate
coated Au
DNA conjugation and electrophoresis of Au nanocrystals
Gel electrophoresis of Au
nanocrystal / DNA conjugates
-> Au nanocrystals with controlled number of DNA molecules
DNA/Au ratio
10 nm Au
100 bases DNA
2% agarose gel
+ HS
DNA can be directly
attached to Au surface
via thiol-linkage
Au and DNA are
negatively charged
+
-
7 V/cm0
1
8 97
6 5
2
3
4
s
Zanchet et al. Nano Letters, 2001, 1, 32.
Isolation of discrete particle groupings by electrophoresis
DNA Directed Assembly of DISCRETE
Colloidal Quantum Dot – Au nanocrystal groupings
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