Nano Chemistry

Scott Group: Nanochemistry

[email protected]

Priya

Mintang

ZahidNicole

Mita

Jina

Thorv 249

Scott Group: NanochemistrySemiconducting CdSe Quantum Dots

Colour changes with Size!

4 nm = 0.000004 mm

Scott Group: NanochemistrySolutions of Gold Nanoparticles also change colour with Size!

Plasmon Band @ ~ 520 nm

• Nanochemistry has old roots• Colloidal Au used in Ancient Roman times • Described by Faraday in 1857 Lycurgus Cup, 300 A.D.

Bimetallic Au-Ag nanoparticleshttp://www.thebritishmuseum.ac.uk

Scott Group: NanochemistryMetal Nanoparticles

Chemistry changes with Size!

Au Au

CO CO2

CO CO2

X See, for example:Valden et al., Science 1998,281, 1647.Scott et al., J. Phys. Chem. B 2005, 109, 692.

Gold Nanoparticles

A

Mita Dasog

• Size control possible by adjusting ratio of HAuCl4 : alkanethiol• Monodispersity can be improved by fractional precipitation• Brust et al., Chem. Commun., 1994, 801.

3.9 ± 0.6 nm

Gold Nanoparticles

A

Mita Dasog

• Size control possible by adjusting ratio of HAuCl4 : alkanethiol• Monodispersity can be improved by fractional precipitation• Brust et al., Chem. Commun., 1994, 801.

Au

S

S

SS

SS

HAuCl4C12H25SH

NaBH4

SO3

Au

S-S

SS

S

Air Exposure SS

Au

S

S

SS

SSSSS

S

SS

S

S

SS

S

S

S-SSO3

B

3.9 ± 0.6 nm 6.2 ± 1.0 nm

Gold Nanoparticles Mita Dasog

• Particle aggregation co-exists with alkanesulfonate formation

• Oxidation of thiols on Au surface by O2!

As synthesized

Air oxidized

Ionic Liquids for Materials Synthesis

Nicole DehmPriyabrat Dash

NN

PF6

AuN N

N

NN

N

N

N

• Liquids at Room Temp. • No vapour pressure• Low surface tension

200 nm

TiCl4

Self-Assembly Hydrolysis

TiO2

One pot synthesis of titania-Au catalysts!

Amine-stabilized AuNanoparticles

Continuing Work

Catalysis with Gold Nanoparticles in Solution

Nicole Dehm

OH

2 atom % Au:PVP300 mol% K2CO3

H2O, air, 300K

O

OH

Benzyl Alcohol Benzoic Acid

Tsunoyama et al., J. Am. Chem. Soc. 2005, 127, 9374.

Barcode Nanowires for Chemical Sensing

Mintang LiuNicewarner-Pena, et al., Science 2001, 294, 137.

Biophysicochemical Properties of Nanoparticles (Bernie Kraatz, Matthew Paige)

Zahid Islam

R R

R

R

R

RR

RR

R

R

R

RR

hv

FRET

emission

R R = NR3+, SO4

-, etc.

How do nanoparticles interact with Lipid membranes?

How does one detect single nanoparticle-biomolecule interactions?

How strongly nanoparticles associatewith biomolecules?