Nanoscience,

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Nanoscience,
Nanotechnology,
and the Environment
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Mike Hochella Joerg Jinschek Deborah
Aruguete Saumyaditya Bose Deric Learman Juan
Liu Kelly Plathe Alison Smith Nick Wigginton
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NANOTECHNOLOGY

• Most current nanomaterials could be organized
  into four types
• CARBON-BASED MATERIALS
• METAL-BASED MATERIALS
• DENDRIMERS
• COMPOSITES

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CdS/CdSe
Quantum dots
Alivisatos (1996) Science
5 nm
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Catalysis gold nanoclusters on TiO2
From Valden et al. (1998) Science Bell (2003)
Science
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? 108 m
? 108 m
nanominerals mineral nanoparticles
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Nanoparticles in the environment
Biosystems
Atmosphere
Soils and plants
Water
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Amphibole
Smectite
Nanotubes
Amphibole
Banfield and Barker (1994) GCA
Nanoforces
Nanofilms
Tingle, Hochella, et al (1990) GCA
PNNL
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Solution chemistry and microbiology
TEM/EELS/SEM
XPS/AES/SIMS
XAS/EXAFS
AFM/STM/TS
Computational chemistry
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EXPOSURE

• INHALATION
• Workplace exposure
• Ambient air
• INGESTION
• Food
• Drinking water
• Incidental
• DERMAL
• Sunscreen
• Cosmetics
• INJECTION
• Drugs

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Fig. 2.  Examples of how ferric iron occurs in
the environment, ranging from the molecular- to
macroscopic scales. Left Molecular ferric oxide
states, including octahedrally coordinated
monomer (hexaquairon III 49) and oligomer
(trimer cluster 50) with Fe3 (smaller dark
red), oxygen (larger light red), and hydrogen
(light pink).  These molecules are hydrogen
terminated, but should only be considered
approximations of actual aqueous/environmental
states.  Middle Polyhedral representations of 1
and 5 nm hematite (Fe2O3) nanoparticles.  Each
polyhedron represents an Fe3 in octahedral
coordination with oxygen.  The thickness of the 5
nm particle should be typically several (roughly
5-7) octahedral layers (24) and the 1 nm particle
just a few octahedral layers.  Right, top to
bottom HRTEM image of hematite nanoparticles
from Namibia (Africa) (sample courtesy of
Smithsonian Institution research collection) TEM
image of unoriented aggregate of 3-5 nm hematite
crystals (stippled portion of the image) from an
acid mine drainage site in Montana (USA) (51)
photograph of macroscopic specular hematite
(courtesy of R. Lavinsky). 
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R. Raiswell et al., Geochim. Cosmochim. Acta 70,
2765 (2006).
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R. Raiswell et al., Geochim. Cosmochim. Acta 70,
2765 (2006).
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Montana, USA
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J. Moore, U. Montana
Butte, Montana
0 km
Clark Fork River
30 km
190 km
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upstream, riverbed
Chalcopyrite (CuFeS2)
(Zn,As,Pb)
Hochella et al. (2005) GCA Hochella et al. (2005)
Am. Min.
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Clark Fork riverbed
Clark Fork floodplain
MnO2 ? nH2O vernadite-like (PbgtCugtZngtAs)
5Fe2O3 ? 9H2O ferrihydrite (CugtPbgtAs)
Hochella et al. (2005) GCA Hochella et al. (2005)
Am. Min.
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Nanoparticles
Mn-oxidation (electron transfer)
Mn2(aq)
Fe oxide
O2
Mn3OOH (s)
Synthetic hematite (a-Fe2O3)
Madden and Hochella (2005) GCA Madden et al.
(2006) GCA
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A
B
Fe oxide
D
C
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Nanoelectronics
Shewanella electron transport chain
Courtesy Brian Lower, PNNL
Nanoparticle bioreduction Bose et al. (in prep)
30 nm
Wigginton et al. (in press) GCA Wigginton et al.
(in prep)
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Total Fe(II) determination by Ferrozine Method
for Initial Rates
Nanoparticle Synthesis
Characterization
Inoculation and Incubation
0.5 N HCl extraction of total Fe(II)
Cell Culture in Chemostat
Determination of Initial Rates
TEM of bioreduced samples
Fe(II) mM/m2
Time in days
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Bose et al., In prep
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11nm Hem
Bose et al., In prep
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12nm Hem
Bose et al., In prep
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99nm Hem
200nm
500 nm
1 µm
1 µm
1 µm
Bose et al., In prep
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30nm Hem
Bose et al., In prep
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44nm Hem
Bose et al., In prep
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Bose et al., In prep
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Wigginton, Hochella, Rosso, Lower, Shi
Mechanisms of interfacial electron transfer
mediated by the decaheme cytochromes
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Nanoelectronics
Shewanella electron transport chain
Courtesy Brian Lower, PNNL
Nanoparticle bioreduction Bose et al. (in prep)
30 nm
Wigginton et al. (in press) GCA Wigginton et al.
(in prep)
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Surface characterization of cytochrome films
Wigginton et al (in press) GCA
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Single-molecule tunneling spectroscopy probes ET
through the cytochromes
Wigginton et al (in press) GCA
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(dI/dV)/(I/V) suggests something else is going on
with MtrC
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Do eox values correlate to redox potentials of
hemes?
UV photoelectron spectroscopy
STM Bias (V)
NHE (eV)
FAu 6.30.1 eV
-1
eox
1
FMtrC 4.60.1 eV
-0.5
0.5
0
0
DF
Hartshorne et al
1.7 eV
0.5
-0.5
1
-1
-1.5
Wigginton et al (in prep)