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Denis Dorokhin (promotion date: 5 February 2010)

Surface engineered quantum dots in photoelectrochemistry and supramolecular assembly

Promotion date: 5. February 2010

Promotor: Prof. Dr. Julius Vancso

The research described in this thesis is concerned with the synthesis, characterization and

application of novel QD materials, and their integration into multilayer structures at

interfaces. In particular, chemical engineering of the QD ligand shell with redox active

molecules and molecules able to take part in supramolecular host-guest reactions, is tackled.

The thesis is focused on ferrocene as the redox molecule and on spectroscopic and

electrochemical evaluation of the interactions between ferrocene and the QD. β-Cyclodextrin

is explored as the molecular host for complexation reactions on the QD surface. Fluorescence

Resonant Energy Transfer and Electron Transfer are explored as signal transduction

mechanisms in surface bound QD-based supramolecular sensing platforms. A strategy for the

functionalization of QDs with electro active polymers is also discussed.

How did the subject for the thesis project evolve in time?

Initially, I was part of the Materials Science and Technology of Polymers, led by professor Julius Vancso. After some organisational changes, I joined the supramolecular chemistry and technology group, headed by professor David Reinhoudt. The subject however remained intact: the modification of quantum dots surface with functional ligands. The obtained new hybrid materials are interesting, due to special optical properties.

There were some peaks and downfalls during this period. Now, three papers already published the results, for example two of them in the ACS Nano Journal, a renowned new journal that is highly ranked. Further, two more papers are under way. Also I performed at a conference in the USA and I was a participant at some international workshops.

How would you describe yourself as a researcher?

I like to design an experiment in a rather profound manner. The ideal situation in my opinion is to perform the experiment, after this preparation, in a few shots. Other experimentalists may find it more suitable to try over and over again. I’m not saying one method is better than the other. It is a matter of style preference.

What are your future plans?

Although the coatings I worked on in my thesis project promise to have applications in the long term future, now I am ready to start working in a more commercial setting. I guess this suits me better, as I am more practical minded. I like the engineering part very much.

I am applying for a post-doc position at Wageningen University, where I’m going to work for the development of biotoxic chips. It feels like a good first step.

All in all, I like to find a next job somewhere in Europe. The cultural background here is closer to that of Russia than for example in the United States. In Russia now the government is investing in nanotechnology research. It takes some time, in my opinion at least five to ten years, before the technology will be on a high enough standard. Perhaps then, one day, I will return as a research leader.

What, you think, is important for Mesa+ to pay attention to in the future?

I really like the open atmosphere. The dynamics within the groups is very good. Sometimes it is necessary to be able to look beyond the expertise of your own group. Of course, good things happen between individuals, seeking contact with each other already. Still, I think on some specific topics more interaction meetings between groups could be organized.