123rd General Meeting of the KCS

Type Oral Presentation
Area Oral Presentation of Young Material Chemists
Room No. Room 405+406
Time THU 09:24-09:36
Code MAT.O-3
Subject Novel Strategies on Preparing Ultrabright Luminescent Gold Nanoclusters via Surface Modification
Authors Kyunglim Pyo, SangMyeong Han1, Hongmei Xu, Dongil Lee*
Department of Chemistry, Yonsei University, Korea
1department of chemistry, Yonsei University, Korea
Abstract On account of the drastic growing interest in developing biological and optical sensing materials, preparing highly luminescent quantum-sized gold nanoclusters(AuNCs) has been one of the actively studied field for the past few decades. However, the low quantum yield(QY<10%) and the uncertainty as to the origin of the luminescence properties are largest obstacle on producing highly luminescent clusters. In this presentation, we present novel strategies for preparing ultrabright luminescent AuNCs by substantially enhancing the luminescence of glutathione(SG) protected Au22SG18 (Au22, QY~7%), via relevant surface modification. Firstly, Au22 was ion-paired with bulky tetraoctylammonium(TOA) cation, which rigidified the Au(I)-thiolate shell structure by significant intermolecule interactions between the alkyl chains. This cluster was confirmed to maintain its composition, while the QY showed a mass increment of 9-fold enhanced luminescence(QY~60%). This is one of the highest QY reported yet for AuNCs. Secondly, Au22 was functionalized with benzyl chloroformate and chromophores which not only rigidified the Au-thiolate shell structure by its aromatic molecules, but also induced resonance energy transfer. As a result, the luminescence increased by 8-fold compared to Au22 which is similar to the TOA bound results. Moreover, this strategy remedies the drawback of the low solubility of TOA-Au in water and obtain highly luminescent water soluble AuNCs. In summary, these two approaches can be widely used to prepare various types of luminescent AuNCs tailored with functional surfaces, which will find a wide range of practical applications in biological imaging as well as luminescent displays.
E-mail mylifetohoi@naver.com