ANTIBACTERIAL, PLASMONIC, AND TOXIC PROPERTIES OF ENGINEERED NANOPARTICLES ...

183 Pages·2016·4.31 MB·English

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
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
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3.1 Introduction ........................................................................................................ 50
3.2 Materials and Methods ....................................................................................... 52
3.2.1 Preparation of chemicals ............................................................................. 52
3.2.2 Gold film silicon substrate .......................................................................... 53
3.2.3 Synthesis of gold nanorods ......................................................................... 53
3.2.4 Fabrication of SERS substrates ................................................................... 54
3.2.5 SERS measurements ................................................................................... 55
3.2.6 Data analysis ............................................................................................... 55
3.3 Results and Discussions ..................................................................................... 57
CHAPTER 4 ..................................................................................................................... 69
Use of Aminothiophenol as an Indicator for the Analysis of Silver Nanoparticles in
Consumer Products by Surface-Enhanced Raman Spectroscopy (SERS) ........................ 69
4.1 Introduction ........................................................................................................ 71
4.2 Materials and Methods ....................................................................................... 74
4.2.1 Materials ..................................................................................................... 74
4.2.2 Characterization of Ag NPs in the products ............................................... 75
4.2.3 Determine Ag NPs in tested products ......................................................... 75
4.2.4 Conjugation of PATP onto Ag NPs ............................................................ 75
4.2.5 Detection of Ag NPs Using SERS and PATP-Ag NPs conjugation ........... 76
4.2.6 Data Analysis .............................................................................................. 76
4.3 Results and Discussion ....................................................................................... 77
CHAPTER 5 ..................................................................................................................... 86
Toxicity of Graphene Oxide on Intestinal Bacteria, and Caco-2 Cells ............................. 86
5.1 Introduction ........................................................................................................ 87
5.2 Materials and Methods ....................................................................................... 89
5.2.1 Characterization of GO ............................................................................... 89
5.2.2 Preparation of Bacterial strains ................................................................... 90
5.2.3 Effect of GO on the growth of E. coli, L. acidophilus, and B. animalis ..... 90
5.2.4 Mammalian cell study ................................................................................. 91
5.2.5 MTT reduction assay .................................................................................. 92
5.2.6 WST-8 proliferation assay .......................................................................... 93
5.2.7 Scanning electron microscopy (SEM) analysis .......................................... 93
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5.2.8 Transmission electron microscopy (TEM) analysis ................................... 94
5.2.9 Statistical analysis ....................................................................................... 94
5.3 Results and Discussion ....................................................................................... 95
CHAPTER 6 ................................................................................................................... 108
Antibacterial Properties of Selenium Nanoparticles and Their Toxicity on Caco-2 Cells
......................................................................................................................................... 108
6.1 Introduction ...................................................................................................... 109
6.2 Materials and Methods ..................................................................................... 110
6.2.1 Chemicals, bacterial strains mammalian cells .......................................... 110
6.2.2 Characterization of Se NPs ....................................................................... 111
6.2.3 Preparation of bacterial strains .................................................................. 112
6.2.4 Synthesis of Se NPs .................................................................................. 112
6.2.5 Effect of Se NPs on the growth of bacterial strains .................................. 113
6.2.6 Mammalian cell study ............................................................................... 113
6.2.7 MTT reduction assay ................................................................................ 114
6.2.8 WST-8 proliferation assay ........................................................................ 114
6.2.9 Scanning electron microscopy (SEM) ...................................................... 115
6.2.10 Transmission electron microscopy (TEM) ............................................... 115
6.2.11 Statistical analysis ..................................................................................... 116
6.3 Results and Discussion ..................................................................................... 116
6.3.1 Characterization of Se NPs ....................................................................... 116
6.3.2 Antibacterial effects of Se NPs on pathogenic bacteria ............................ 118
6.3.3 Cytotoxic effect of Se NPs on Caco-2 cells .............................................. 124
CHAPTER 7 ................................................................................................................... 128
Conclusions and Future Plans ......................................................................................... 128
Appendix ......................................................................................................................... 131
References ....................................................................................................................... 132
VITA ............................................................................................................................... 169

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LIST OF TABLES
Table Page
Table 1. Food and Food-related products that claim to contain nanoparticles ................... 6
Table 2. Antibacterial effect of inorganic ENPs against different microorganisms ......... 20
Table 3. In vitro cytotoxicity effects of graphene materials and Se NPs .......................... 33
Table 4. Band assignment of major peak in SER spectra form three pesticides* ............ 63
Table 5. Limit of detection of using G-Au-AuNRS substrate for detection of azinphos-
methyl, carbaryl, and phosmet .......................................................................................... 68
Table 6. Total concentration of silver and Ag NPs, average size, and the intensity of SERS
spectra acquired from five commercial products .............................................................. 84
Table 7. GO characteristics, values presented means ± SD from triplicate measurements.
........................................................................................................................................... 97
Table 8. The zeta-potential values of selenium nanoparticles. ....................................... 118
Table 9. Zeta potential values of bacteria strains ............................................................ 124

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LIST OF FIGURES
Figure Page
Figure 2-1. Schematic of a surface-enhanced light scattering process (Schatz and others
2006; Alonso-González and others 2012)......................................................................... 14
Figure 3-1. Structure of substrates: (a) graphene-Au-AuNR (G-Au-AuNR); (b) graphene-
AuNR (G-AuN); (c) Au-AuNR. ....................................................................................... 54
Figure 4-1. SERS spectra of PATP, PATP mixed with AgNO , PATP with 30 nm Ag NP .
3 3
........................................................................................................................................... 78
Figure 4-2. Comparisons of enhancement effects from Ag NPs. ..................................... 79
Figure 4-3. Concentration-dependent SERS spectra (part of full scale) of Ag NPs with
PATP (10 mg/mL) as an indicator (A); the linear relation between Raman intensity and Ag
NPs concentration (B). ...................................................................................................... 80
Figure 4-4. SERS spectra four five Ag NPs-containing dietary and antimicrobial products.
Negative controls were prepared using the solvent of PATP (methanol). ........................ 82
Figure 4-5. Characterization of Ag NPs in the dietary supplements and antimicrobial
products. (A) Dietary supplement; (B) nasal spray; (C) dietary supplement; (D) dietary
supplement; (E) dietary supplement. ................................................................................ 83
Figure 5-1. UV–vis absorption spectrum of GO aqueous dispersion (A). FTIR spectrum of
dried graphite oxide sample (B). ....................................................................................... 96
Figure 5-2. TEM images of GO aqueous dispersion ........................................................ 96
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