13.12.2019 Study of water-soluble p-MBA-protected gold nanoclusters and their superstructures (Sokolowska)

At the Ä¢¹½Ö±²¥ Karolina Sokolowska’s dissertation thesis focuses on atomically-precise gold nanoclusters and their superstructures. Gold nanoclusters were covalently-linked together through the molecular bridges producing different sizes of oligomers. The newly created system exhibits additional transitions in their UV-vis spectrum indicating the presence of hybridized plasmon modes. These structures allow accurate studies of light-matter interaction in metallic nanostructure at a quantum level opening new possibilities in the development of nanoplasmonic sensors and devices.
Published
13.12.2019

Gold nanoclusters have a specific number of atoms in a well-organized structure, similar to molecule enabling accurate studies of their chemistry as well as a direct comparison of experimental and theoretical results.

The nanoclusters studied in this thesis are protected by the ligand layer, which plays a significant role in their properties offering endless possibilities for the rational design and functionalization of the surface layer. 

In this study, a  straightforward, general and up-scalable synthesis to covalently-linked individual gold nanoclusters forming bigger nanostructures was developed.  Gold nanoclusters were linked with molecular bridges forming pairs, tringles, and chains of nanoparticles. 

Light alters the electric field between clusters leading to changes in optical properties

To understand the physics of many optical phenomena in the nanoscale system the detailed knowledge of the chemical structure and forces governing the formation of the systems is required. Therefore, each of the gold nanocluster fractions was purified and separated forming single-sized constructs. 

The studies have shown that the newly developed system is in dynamic equilibrium where nanoclusters are bound together by a short chain of disulfide-bridged dithiols. Such a controlled assembly of gold nanoclusters into well-defined structures created a system with new optical properties. The interaction of these structures with light alters the electric field between clusters leading to changes in their optical properties. These properties hold potential in several sensor-based applications.

The dissertation series, in JYU Dissertation series, 167, Ä¢¹½Ö±²¥, Jyväskylä, 2019 series, ISSN 2489-9003, 167, ISBN 978-951-39-7966-9

Link to publication: 

Karolina Sokolowska defends her doctoral dissertation in the subject "Study of water-soluble p-MBA-protected gold nanoclusters and their superstructures" on Friday 13 of December at Ylistönrinne lecture hall KEM4 at 12 o’clock. The Opponent is Associate Professor Jianping Xie from the National University of Singapore and Custos is Docent Tanja Lahtinen from the Ä¢¹½Ö±²¥. The doctoral dissertation is held in English.

For further information:
Karolina Sokolowska, karolina.x.sokolowska@jyu.fi
Communications officer Tanja Heikkinen, tanja.s.heikkinen@jyu.fi, tel. +358 50 581 8351
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