Surface engineered quantum dots in photoelectrochemistry and supramolecular assembly

Denis Viktorovich Dorokhin

Research output: ThesisPhD Thesis - Research UT, graduation UT

70 Downloads (Pure)

Abstract

This thesis demonstrates the power of chemical surface engineering in the design and fabrication of functional hybrid materials made of Quantum Dots. The small size of the QDs, in the range of 1 to 10 nm, and related stability in solution, require a careful consideration of a proper surface chemistry for the ligand shell. By a judicious choice of the coating one can remarkably influence the physicochemical and photophysical properties of the semiconductor nanocrystals as well as design and engineer new generations of advanced nanoscale materials. This work describes in detail the synthetic approaches to chemical surface functionalization of QDs with electroactive ligands, including ferrocenyl thiols and poly(ferrocenylsilanes), and with β-cyclodextrin (β-CD) ligands suitable for supramolecular host-guest assembly. These functional ligands are shown to be important components in the engineering of new types of QD hybrid materials. The influence of the electroactive ligands on the optical properties of QDs was investigated by spectroscopic and electrochemical methods. These investigations gave an important insight into the quenching mechanisms of QDs by ferrocene and to the fundamental electron transfer processes in hybrid materials composed of QDs and electro-active ligands. Additionally, ferrocene groups located on the QD surface were shown to be able to take part in host-guest complexation reactions with β-cyclodextrin in solution. This ability was useful in the phase transfer of hydrophobic nanoparticles between solvents of markedly different polarities. The complexation ability of β-CD-functionalized QDs and adamantyl dendrimers was exploited for the preparation of supramolecular multilayer structures on surfaces. Surface bound QDs were shown to be able to transduce optically the binding events to the β-CD cavity, a proof-of-principle for a sensor design. This thesis demonstrates that both FRET and ET can be used as the transduction mechanisms. Thus, proper surface design and engineering of QDs gives unique opportunities to obtain the new class of hybrid materials using numerous functionalization approaches and surface chemistries.
Original languageEnglish
Awarding Institution
  • University of Twente
Supervisors/Advisors
  • Vancso, Gyula J., Supervisor
  • Reinhoudt, David Nicolaas, Supervisor
  • Tomczak, N., Co-Supervisor
  • Velders, A.H., Co-Supervisor
Award date5 Feb 2010
Place of PublicationEnschede
Publisher
Print ISBNs978-90-365-2977-8
DOIs
Publication statusPublished - 5 Feb 2010

Fingerprint

Semiconductor quantum dots
Hybrid materials
Ligands
Cyclodextrins
Surface chemistry
Complexation
Dendrimers
Functional materials
Sulfhydryl Compounds
Nanocrystals
Quenching
Multilayers
Optical properties
Semiconductor materials
Nanoparticles
Engineers
Fabrication
Coatings
Electrons
Sensors

Keywords

  • IR-69953

Cite this

Dorokhin, Denis Viktorovich. / Surface engineered quantum dots in photoelectrochemistry and supramolecular assembly. Enschede : University of Twente, 2010. 136 p.
@phdthesis{dc48b3ddf0144065a0644299ff4e8aba,
title = "Surface engineered quantum dots in photoelectrochemistry and supramolecular assembly",
abstract = "This thesis demonstrates the power of chemical surface engineering in the design and fabrication of functional hybrid materials made of Quantum Dots. The small size of the QDs, in the range of 1 to 10 nm, and related stability in solution, require a careful consideration of a proper surface chemistry for the ligand shell. By a judicious choice of the coating one can remarkably influence the physicochemical and photophysical properties of the semiconductor nanocrystals as well as design and engineer new generations of advanced nanoscale materials. This work describes in detail the synthetic approaches to chemical surface functionalization of QDs with electroactive ligands, including ferrocenyl thiols and poly(ferrocenylsilanes), and with β-cyclodextrin (β-CD) ligands suitable for supramolecular host-guest assembly. These functional ligands are shown to be important components in the engineering of new types of QD hybrid materials. The influence of the electroactive ligands on the optical properties of QDs was investigated by spectroscopic and electrochemical methods. These investigations gave an important insight into the quenching mechanisms of QDs by ferrocene and to the fundamental electron transfer processes in hybrid materials composed of QDs and electro-active ligands. Additionally, ferrocene groups located on the QD surface were shown to be able to take part in host-guest complexation reactions with β-cyclodextrin in solution. This ability was useful in the phase transfer of hydrophobic nanoparticles between solvents of markedly different polarities. The complexation ability of β-CD-functionalized QDs and adamantyl dendrimers was exploited for the preparation of supramolecular multilayer structures on surfaces. Surface bound QDs were shown to be able to transduce optically the binding events to the β-CD cavity, a proof-of-principle for a sensor design. This thesis demonstrates that both FRET and ET can be used as the transduction mechanisms. Thus, proper surface design and engineering of QDs gives unique opportunities to obtain the new class of hybrid materials using numerous functionalization approaches and surface chemistries.",
keywords = "IR-69953",
author = "Dorokhin, {Denis Viktorovich}",
year = "2010",
month = "2",
day = "5",
doi = "10.3990/1.9789036529778",
language = "English",
isbn = "978-90-365-2977-8",
publisher = "University of Twente",
address = "Netherlands",
school = "University of Twente",

}

Surface engineered quantum dots in photoelectrochemistry and supramolecular assembly. / Dorokhin, Denis Viktorovich.

Enschede : University of Twente, 2010. 136 p.

Research output: ThesisPhD Thesis - Research UT, graduation UT

TY - THES

T1 - Surface engineered quantum dots in photoelectrochemistry and supramolecular assembly

AU - Dorokhin, Denis Viktorovich

PY - 2010/2/5

Y1 - 2010/2/5

N2 - This thesis demonstrates the power of chemical surface engineering in the design and fabrication of functional hybrid materials made of Quantum Dots. The small size of the QDs, in the range of 1 to 10 nm, and related stability in solution, require a careful consideration of a proper surface chemistry for the ligand shell. By a judicious choice of the coating one can remarkably influence the physicochemical and photophysical properties of the semiconductor nanocrystals as well as design and engineer new generations of advanced nanoscale materials. This work describes in detail the synthetic approaches to chemical surface functionalization of QDs with electroactive ligands, including ferrocenyl thiols and poly(ferrocenylsilanes), and with β-cyclodextrin (β-CD) ligands suitable for supramolecular host-guest assembly. These functional ligands are shown to be important components in the engineering of new types of QD hybrid materials. The influence of the electroactive ligands on the optical properties of QDs was investigated by spectroscopic and electrochemical methods. These investigations gave an important insight into the quenching mechanisms of QDs by ferrocene and to the fundamental electron transfer processes in hybrid materials composed of QDs and electro-active ligands. Additionally, ferrocene groups located on the QD surface were shown to be able to take part in host-guest complexation reactions with β-cyclodextrin in solution. This ability was useful in the phase transfer of hydrophobic nanoparticles between solvents of markedly different polarities. The complexation ability of β-CD-functionalized QDs and adamantyl dendrimers was exploited for the preparation of supramolecular multilayer structures on surfaces. Surface bound QDs were shown to be able to transduce optically the binding events to the β-CD cavity, a proof-of-principle for a sensor design. This thesis demonstrates that both FRET and ET can be used as the transduction mechanisms. Thus, proper surface design and engineering of QDs gives unique opportunities to obtain the new class of hybrid materials using numerous functionalization approaches and surface chemistries.

AB - This thesis demonstrates the power of chemical surface engineering in the design and fabrication of functional hybrid materials made of Quantum Dots. The small size of the QDs, in the range of 1 to 10 nm, and related stability in solution, require a careful consideration of a proper surface chemistry for the ligand shell. By a judicious choice of the coating one can remarkably influence the physicochemical and photophysical properties of the semiconductor nanocrystals as well as design and engineer new generations of advanced nanoscale materials. This work describes in detail the synthetic approaches to chemical surface functionalization of QDs with electroactive ligands, including ferrocenyl thiols and poly(ferrocenylsilanes), and with β-cyclodextrin (β-CD) ligands suitable for supramolecular host-guest assembly. These functional ligands are shown to be important components in the engineering of new types of QD hybrid materials. The influence of the electroactive ligands on the optical properties of QDs was investigated by spectroscopic and electrochemical methods. These investigations gave an important insight into the quenching mechanisms of QDs by ferrocene and to the fundamental electron transfer processes in hybrid materials composed of QDs and electro-active ligands. Additionally, ferrocene groups located on the QD surface were shown to be able to take part in host-guest complexation reactions with β-cyclodextrin in solution. This ability was useful in the phase transfer of hydrophobic nanoparticles between solvents of markedly different polarities. The complexation ability of β-CD-functionalized QDs and adamantyl dendrimers was exploited for the preparation of supramolecular multilayer structures on surfaces. Surface bound QDs were shown to be able to transduce optically the binding events to the β-CD cavity, a proof-of-principle for a sensor design. This thesis demonstrates that both FRET and ET can be used as the transduction mechanisms. Thus, proper surface design and engineering of QDs gives unique opportunities to obtain the new class of hybrid materials using numerous functionalization approaches and surface chemistries.

KW - IR-69953

U2 - 10.3990/1.9789036529778

DO - 10.3990/1.9789036529778

M3 - PhD Thesis - Research UT, graduation UT

SN - 978-90-365-2977-8

PB - University of Twente

CY - Enschede

ER -