Antibacterial, plasmonic and toxic properties of engineered nanoparticles :Doctor of Philosophy - Departmentof Human Nutrition

ANTIBACTERIAL, PLASMONIC, AND TOXIC PROPERTIES OF ENGINEERED

NANOPARTICLES

A Thesis presented to the Faculty of the Graduate School

University of Missouri

In Partial Fulfillment

of the Requirements for the Degree

Doctor of Philosophy

by

Trang Ha Dieu Nguyen

Drs. Mengshi Lin, Azlin Mustapha Thesis Supervisors

DECEMBER 2016

© Copyright by Trang Ha Dieu Nguyen 2016

All rights reserved.

The undersigned, appointed by the dean of the Graduate School, have examined the thesis

entitled

ANTIBACTERIAL, PLASMONIC AND TOXIC PROPERTIES OF ENGINEERED

NANOPARTICLES

Presented by Trang Ha Dieu Nguyen,

a candidate for the degree of Doctor of Philosophy,

and hereby certify that, in their opinion, it is worthy of acceptance.

Mengshi Lin, Ph.D., Food Science Program

Azlin Mustapha, Ph.D., Food Science Program

Bongkosh Vardhanabhuti, Ph.D., Food Science Program

Chong He, Ph.D., Department of Statistics

ii

ACKNOWLEDGEMENTS

In the heat of moment, when many ideas for the acknowledgment part of my dissertation

come along, I was so excited. This dissertation took me four and a half years and it has

given me much of challenges and joyfulness. This work would not have been possible

without the guidance and supports of all the following individuals. First and foremost, I

would like to thank my two wonderful advisors, Drs. Mengshi Lin and Azlin Mustapha.

Dr. Lin is a facilitator and a mentor who abundantly helped and offered me invaluable

assistance, supports and encouragements during my time in Mizzou. I believe he spent

hundreds of hours editing my manuscripts, even in the weekends. Dr. Mustapha inspired

me by her enthusiasm, energy, and excellent knowledge. I cannot fulfill my dissertation

without her advice and guidance when I had problems with my experiments. She is the

person who has proven that a female scientist can balance well between her family and

career!

I would like to show my gratitude to my committee members, Dr. Vardhanabhuti and

Dr. He through the journey. I appreciate their valuable suggestions and comments,

especially Dr. V for her co-authorship in one of my manuscripts.

I also would like to express my thanks to Dr. Koc, Dr. Clarke, Dr. Gruen, Dr. Elmore,

Dr. Alexander for letting me help them in teaching assistance. I have learned from them

teaching methods, curricula and appropriate manner when interacting with students.

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I thank my past and present lab members and from different labs for being wonderful

colleagues to work with. Special thanks are given to Zhang Zhong for his co-authorship

and assistance.

I acknowledge the Vietnam International Education Development under the Ministry of

Education and Training for financial support in the first two years of my study.

Finally, I owe my deepest gratitude to my family in Vietnam and my husband’s family

in the US for endless love, support, and encouragement, without which I could not finish

my work. My husband and my sons Yanni and Raphael are the greatest gifts that God

brought to me. Thank you all for being with me, loving me unconditionally, being my

support and inspiring me every single day of my life.

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TABLE OF CONTENTS

ACKNOWLEDGEMENTS................................................................................................ ii

LIST OF TABLES............................................................................................................ vii

LIST OF FIGURES ......................................................................................................... viii

ABSTRACT....................................................................................................................... xi

CHAPTER 1 ....................................................................................................................... 1

Introduction......................................................................................................................... 1

1.1 Background .......................................................................................................... 1

1.2 Objectives.................................................................................................................. 3

CHAPTER 2 ....................................................................................................................... 5

Literature review................................................................................................................. 5

2.1 Nanomaterials and current uses in foods and consumer products ....................... 5

2.2 Surface enhanced Raman spectroscopy (SERS) and its enhancement mechanisms

13

2.3 Applications of SERS for Food Adulterant Detection....................................... 17

2.4 SERS substrates.................................................................................................. 18

2.5 Antibacterial properties of inorganic ENPs ....................................................... 20

2.6 Mechanisms of antimicrobial properties of inorganic ENPs ............................. 26

2.7 Physical and chemical properties of inorganic ENPS affect their antimicrobial

activities ........................................................................................................................ 29

2.8 Cytotoxicity of inorganic NPs to human cells ................................................... 32

2.9 Mechanisms of cytoxocity of ENPS .................................................................. 35

2.10 Physical and chemical properties of NMs associated with nanotoxicity ........... 36

2.11 Toxicity Assessment of NPs .............................................................................. 39

2.11.1 Cell uptake .................................................................................................. 40

2.11.2 Cell viability................................................................................................ 41

2.11.3 Cell functions.............................................................................................. 41

CHAPTER 3 ..................................................................................................................... 48

Use of Graphene and Gold Nanorods as Substrates for Detection of Pesticides by Surface

Enhanced Raman Spectroscopy........................................................................................ 48