Noble-metal nanoparticles produced with colloidal lithography [Elektronische Ressource] : fabrication, optical properties and applications / vorgelegt von Noelia Laura Bocchio

Noble-metal nanoparticles produced with colloidal
lithography: fabrication, optical properties and
applications











Dissertation


zur Erlangung des akademischen Grades des Dr. rer. nat.
im Fachbereich Chemie der Johannes Gutenberg-Universität Mainz












vorgelegt von

Noelia Laura Bocchio

geboren in Rosario, Argentinien







Mainz, August 2008








































Diese Arbeit wurde in der Zeit von Mai 2005 bis August 2008 am Max-
Planck-Institut fuer Polymerforschung in Mainz angefertigt.

The work for this dissertation was carried out between May 2005 and August
2008 at the Max-Planck-Institute for Polymer Research in Mainz (Germany).

Financial support: Max Planck Gesellschaft, Bundesministerium für Bildung
und Forschung





























Zwei Dinge sind zu unserer Arbeit nötig:
Unermüdliche Ausdauer und die Bereitschaft, etwas, in das man viel Zeit und Arbeit
gesteckt hat, wieder weg zu werfen.


Albert Einstein
Table of contents


1 Introduction...................................................................................................... 11

Metallic nanoparticles and their applications ..............................................11

Plasmons ...................................................................................................11
Plane interfaces................................................................................................. 12
Plasmon resonances in metallic nanoparticles .................................................. 13
Objective and main structure of this work...................................................17

2 Fabrication ....................................................................................................... 21
2.1 Single, isolated nanocrescents on a flat substrate...........................23
2.1.1 Sample preparation ............................................................................. 23
2.1.2 Geometrical description....................................................................... 25
2.1.3. Standard crescent shaped nanoparticles................................................. 26
2.2 Close-packed arrangements of nanocrescents ...............................27

2.2.1 Fabrication of a mask of evenly spaced colloids ................................. 28
2.2.2 Controlled particle size reduction ........................................................ 28
2.2.3 Fabrication of the crescent shaped structures..................................... 29
2.3 Surface tailoring I: Thin films on metal nanostructures ....................31
2.3.1 Preparation of thin films and surfaces ................................................. 31
2.3.2 Surface functionalization ..................................................................... 32
2.3.3 Polyelectrolyte attachment .................................................................. 33
2.4 Surface tailoring II: surface modification for the study of bio-
recognition events ......................................................................................39
2.4.1 Biotinylation ......................................................................................... 39
2.4.2 Streptavidin (SAv) attachment............................................................. 39
2.4.3 Bioconjugation of the SAv-modified Au nanoparticles (SAv-
AuNPs) 39
2.5 Summary .........................................................................................40

3 Understanding resonances ............................................................................ 41
3.1 Isolated particles..............................................................................41

3.1.1 Varying ϕ structures ............................................................................ 42
3.1.2 Metal thickness ( t ) ............................................................................. 53
3.1.3 Colloidal size (d ) .............................................................................. 53 coll
3.1.4 Metal deposition angle (θ ).................................................................. 56 i
3.1.5 Etching angle (ε).................................................................................. 58
3.1.6 Materials.............................................................................................. 58
3.2 Close-packed crescent shaped nanostructures...............................60

3.2.1 Experimental ....................................................................................... 60
3.2.2 Results and discussion........................................................................ 61
3.3 Summary and conclusions...............................................................64

4 - Sensing with crescent shaped nanoparticles............................................. 66
4.1 Introduction......................................................................................66
4.2 Thin layer sensing with multipolar resonances ................................68

4.2.1 Sample preparation ............................................................................. 68
4.2.2 Characterization .................................................................................. 68
4.2.3 Results and discussion........................................................................ 69
4.3 Testing the sensing capabilities of the nanocrescents for bio-
recognition events ......................................................................................81
4.3.1 Sample preparation ............................................................................. 82
4.3.2 Characterization .................................................................................. 82
4.3.3 Results and discussion........................................................................ 83
4.4 Conclusions.....................................................................................88

5 - Fluorophores close to crescent shaped nanoparticles ............................. 90
5.1 Two-photon excitation......................................................................91
5.2 Experimental....................................................................................92

5.2.1 Sample preparation ............................................................................. 92
5.2.2 Characterization .................................................................................. 93
5.3 Results and discussion....................................................................95
5.4 Summary and conclusions.............................................................108

6 - Fabrication of discs and ellipsoid-like noble metal nanoparticles.......... 111
6.1 Introduction and motivation............................................................111
6.2 Fabrication.....................................................................................112

6.2.1 General methodology ........................................................................ 112
6.2.2 Sample preparation ........................................................................... 113

6.3. Characterization ................................................................................114
6.3 Results and discussion..................................................................114

6.3.1 Nanodiscs (ε = 0°) ............................................................................. 114
6.3.2 Ellipsoids (ε > 0) ................................................................................ 121
6.4 Conclusions...................................................................................125

7 - Sensing with metallic nanodiscs ............................................................... 126
7.1 Thin film sensing with Au nanodiscs..............................................127

7.1.1 Experimental ..................................................................................... 127
7.1.2 Characterization ................................................................................ 128
7.1.3 Results and discussion...................................................................... 128
7.2 Sensing of bio-recognition events with nanodiscs .........................132

7.2.1 Experimental ..................................................................................... 132
7.2.2 Results and discussion...................................................................... 132
7.3 Conclusions...................................................................................137

8 - Tailoring plasmon resonances –