Switchable assembly of stable ordered molecular layers [Elektronische Ressource] : towards a reversible biosensor platform / von: Ravindra R. Deshmukh

Ravindra

Informations

• Publié par: technischen_universitat_dortmund
• Publié le: 01 janvier 2006
• Nombre de lectures: 21
• Langue: English
• Poids de l'ouvrage: 7 Mo

Extrait

SWITCHABLE ASSEMBLY OF STABLE ORDERED
MOLECULAR LAYERS:
TOWARDS A REVERSIBLE BIOSENSOR
PLATFORM



Dem Fachbereich Chemie der Universität Dortmund
zur Erlangung des akademischen Grades eines
Doktor der Naturwissenschaften
(Dr. rer. Nat.)
vorgelegte Dissertation


von:

M. Sc. Ravindra R. Deshmukh

Geboren am 11.09.1975
In Jalana, Indien



Betreuer: Priv. Doz. Dr. Börje Sellergren
Koreferrent: Univ.-Prof. Dr. Roland Winter



Universität Dortmund, Institut für Umweltforschung
March 2006
ACKNOWLEDGMENTS

I take this opportunity to convey my deepest sense of gratitude to all those who
helped me in my thesis work.
First and foremost, I would like to thank my supervisor, PD Dr. Börje Sellergren for
giving me the opportunity to work in the field of Self-Assembled Monolayers (SAMs)
and for constant support and guidance throughout this work.
I also thank Prof. Dr. Michael Spiteller, Head, INFU, for the nice atmosphere and
working environment during this thesis work.
I would like to thank Dr. Andrew J. Hall, Dr. Eric Schillinger, Dr. Marco Emgenbroich
and Dr. Francesca Lanza-Sellergren for creative guidance, invaluable help and
friendly discussions during the work. Very special thanks to Dr. Jeroen Verhage
(specially for the crate of Hövels, which has driven me to finish my thesis in time!!!!)
for helpful discussions and constructive suggestions during thesis writing.
My special thanks to Dr. F. Katzenberg for contact angle measurements, Dr. J.
Baranski, and Dr. Ioana Pera for Atomic Force Microscopy measurements and
Robert Stonies for gold evaporations.
I would like to thank especially all the members of Sellergren group (present and
former) featuring in no particular order as such, Dr. Sandra Pati, Dr. Panagiotis
Manesiotis, Dr. Maria-Magdalena Titirici, Dr. Yasumasa Kenekiyo, Carla Aureliano,
Filipe Vilela, Cristiana Borrelli, Issam Lazraq, Bettina Hofmann, Kim Schwarzkopf,
Anupkumar, for nice working atmosphere and for their wonderful advices and
support during my stay in the group.
I would like to thank my teachers Prof. M.N. Deshpande, Dr. R. J. Lahoti, Dr. K.V.
Srinivisan, Dr. U. R. Kalkote and Dr. S.R Bhusare for their helpful guidance during
my early stages of the research work.
Last but definitely not the least; I owe my immense gratitude to my parents for their
continuous support, blessings and their encouragement throughout my research
work.
Financial support from Deutsche Forschungsgemeinschaft (DFG) Project: Se 777/2-
5) is thankfully acknowledged.

2Table of contents

Table of contents

1 Zusammenfassung ......................................................................................7
2 Summary....................................................................................................10
3 Introduction................................................................................................13
3.1 Self-assembled monolayers .................................................................13
3.2 Preparation of gold surfaces18
3.3 Synthesis of self-assembled monolayers of alkanethiols......................21
3.4 Terminal groups that produce high energy surfaces.............................24
3.5 Terminal groups that produce surfaces with intermediate energies......25
3.6 Terminal groups that produce low energy surfaces ..............................25
3.7 Use of polar surface for covalent and non-covalent attachment...........26
3.8 Alkanethiols containing aromatic structures..........................................27
3.9 Self-assembled monolayer as biosensor platform ................................27
3.10 Switchable surfaces..............................................................................28
3.11 The amidinium-carboxylate ion pair......................................................30
3.12 Self-assembled monolayers of Mercaptohexadecanoic Acid (MHA) ....31
3.13 References ...........................................................................................34
4 Results and Discussion ............................................................................39
4.1 Synthesis of hetrofunctionalized amphiphiles.......................................39
4.2 Adsorption of single component amphiphiles on gold surfaces ............41
4.2.1 In-situ ellipsometry.........................................................................42
4.2.2 Air eeellipsometry..........................................................................44
4.2.3 The influence of pH on the layer thickness....................................45
4.2.4 Infrared reflection absorption spectroscopy (IRAS) .......................50
4.2.5 Contact angle measurements........................................................56
4.3 Mixed self-assembled monolayers OCH and NO amphiphiles...........58 3 2
4.3.1 In-situ ellipsometry.........................................................................59
4.3.2 The influence of pH on the mixed self-assembled monolayers .....61
4.3.3 IRAS of mixed SAMs of ................................................................62
4.3.4 Contact angle measurements71
4.4 Mixed self-assembled monolayers of OCH and C(=NH)NH ...............72 3 2
4.4.1 In-situ ellipsometry.........................................................................73
4.4.2 The influence of pH on mixed self-assembled monolayers ...........74
4.4.3 IRAS of mixed SAMs of OCH and C(=NH)NH ............................76 3 2
4.4.4 Contact angle measurements........................................................81
4.5 Atomic force microscopy (AFM)............................................................82
4.5.1 AFM of single component monolayers .........................................85
4.5.2 AFM of mixed coayers ..........................................91
4.5.3 Conclusions...................................................................................92
4.6 Introducing bioaffinity ligands at ω-position of the amphiphiles ............95
4.6.1 Synthesis of ω-functionalized biotinylated amphiphiles.................96
4.6.2 In situ ellipsometry.........................................................................97
4.6.3 IRAS of hydroxide and biotin functionalized amphiphiles ............100
4.7 Mixed SAMs of hydroxide and biotin functionalized amphiphiles........103
4.7.1 Air ellipsometry............................................................................104
3Table of contents

4.7.2 IRAS of mixed SAMs hydroxide and biotin amphiphiles..............107
4.7.3 IRAS study of the adsorption of streptavidin (SA) on mixed SAMs of
hydroxide and biotin functionalized amphiphiles........................................109
4.7.4 Conclusions.................................................................................115
4.8 Switchable assembly of α, ω-bis(4-amidinophenylamine)alkanes.......116
4.8.1 In situ ellipsometry.......................................................................117
4.8.2 IRAS of α, ω-bis(4-amidinophenylamine)alkanes.........................120
4.8.3 Contact angle measurements......................................................122
4.8.4 Conclusions123
4.9 Introducing amide linkages in the amphiphiles ...................................124
4.10 References .........................................................................................126
5 Experimental Part ....................................................................................130
5.1 Synthesis of α, ω-hetero-functionalized amphiphiles...........................130
5.1.1 Synthesis of 4-cynophenoxyoctane-8 bromide............................130
5.1.2 Synthesis 4-methylphenoxy (4-cynophenoxy)octane ..............131
5.1.3 Synthesis of 4-methylphenoxy(4-amidinophenoxy)octane
hydrochloride .............................................................................................132
5.1.4 Synthesis of 4-nitrophenoxy(4-cynophenoxy)octane...................133
5.1.5 Synthesis of 4-nitrophenoxy(4-amidinophenoxy)octane
hydrochloride134
5.1.6 Synthesis of 4-methoxyphenoxy(4-cynophenoxy)octane ............135
5.1.7 Synthesisophenoxy(4-amidino
hydrochloride136
5.2 Synthesis of α, ω-bis(4-amidinophenylamine)alkanes.........................137
5.2.1 Synthesis of 1,9-bis (4-cyanophenylamine) nonane (Nonamidine)
137
5.2.2 Synthesis of 1,9-bis (4-amidinophenylamine) nonane
dihydrochloride (Nonamidine)....................................................................138
5.2.3 Synthesis of 1,10-bis (4-cyanophenylamine) decane (decamidine)
139
5.2.4 Synthesis of 1,10-bis (4-amidinophenylamine) decane
dihydrochloride (decamidine).....................................................................140
5.2.5 Synthesis of 1,12-bis (4-cyanophenylamine) dodecane
(dodecamidine)..........................................................................................141
5.2.6 Synthesis of 1,12-bis (4-amidinophenylamine) dodecane
dihydrochloride (dodecamidine).................................................................142
5.2.7 Synthesis of 1,8-bis (4-cyanophenylamide).................................143 <