Results

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Photoluminescence and scattering of gold nanorods.

AcknowledgementsI would like to thank my mentor, Anneli Hoggard, for

guiding me through this experiment and to Joey Tauzin for assisting me with my poster. I would also like to thank Rice University chemistry department and Dr. Stephan Link for allowing me to work in his lab.

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Conclusion

The addition of methyl viologen to the gold nanoparticles had a significant change on its scattering spectra, but not its luminescence. The changes that were observed in both concentrations, more notably in 1 M MV, were: a red shift, a widening of the spectra, and a slight decrease in intensity. This proves that photoluminescence is more stable in electron withdrawing environments.

Biological ApplicationsNanoparticles have a huge potential in the

biological field. They can be great imaging probes in cells because they are background free, bright and stable. They can also be used in the delivery of drugs to specific parts of the body. However, before they can be used commercially, they need to be understood fully and be measured predictably and accurately.

Dark-field image of red nanoparticles inside live pancreatic cancer cells1.

1Hu, R.; Yong, K.T.; Roy, I.; Ding, H.; He, S.; Prasad, P.N. J. Phys. Chem. C. 2009, 113(7), 2676-2684.

Microscope Setup

CCD

Spectrometer White light

APD

532 nm laser

or

Dark-field scattering

Luminescence

CCD = Charge Coupled device APD = Avalanche Photo Diode

Experimental ProceduresCamera Image

061213a_059.dat

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061413a_100.dat

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Luminescence

1. Microscope calibrated to receive maximum counts.2. Camera image3. APD image4. Single Particle Spectra5. Data analysis (Matlab, background correction,

white light standard correction)

N NCl- Cl-

Structure of Methyl Viologen (MV)

Plasmon Resonance in Noble Metal NanostructuresGuillermo Lash1, Anneli Hoggard2, Dr. Stephan Link2

1 Science Academy of South Texas 2 Dept. of Chemistry, Rice University

Charge Cloud of Conduction Electrons

Nuclear Framework of Nanoparticle

E-Field

e- Cloud

Plasmon Resonance is the collective oscillation of electrons in a solid or liquid stimulated by incident light and is the basis of many biomedical and materials applications. Before metal nanoparticles can be used in these applications, we must understand their fundamental properties.

Introduction

To determine how gold nanorods change their light scattering through their interactions with other molecules such as methyl viologen.

Bottle containing a solution of gold nanorods

The sonicator was used to break up aggregates in solution

Special quartz slides with nanogrid

Spin coater evenly spreads gold nanorods and methyl viologen

Sample Preparation

1. Gold nanorod solution was stirred using sonicator

2. Quartz slides were peeled and placed on spin coater

3. Solution was pipetted onto the slides4. Spin coater was activated and solution spread

out evenly on the surface of the slides.

Objective