Interband Absorption Enhanced Optical Activity in Discrete Au@Ag Core–Shell Nanocuboids: Probing Extended Helical Conformation of Chemisorbed Cysteine Molecules. (22nd December 2016)

• Record Type: Journal Article
• Authors: Bao, Zhi Yong; Zhang, Wei; Zhang, Yong‐Liang; He, Jijun; Dai, Jiyan; Yeung, Chi‐Tung; Law, Ga‐Lai; Lei, Dang Yuan
• Is Part Of: Angewandte Chemie. Volume 129:Number 5(2017)
• Page Start: 1303
• Page End: 1308
• Publication Date: 2016-12-22
• Subjects: Interbandübergang -- Metallnanostrukturen -- Optische Aktivität -- Strukturelle Konformation -- Zirkulardichroismus; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201607563
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Detailed understanding of the interaction between a chiral molecule and a noble metal surface is essential to rationalize and advance interfacial self‐assembly of amino acids and metal‐mediated anchoring of proteins. Here we demonstrate that individual Au@Ag core–shell nanocuboids can serve as a plasmonic reporter of an extended helical network formed among chemisorbed cysteine molecules, through generating an interband absorption enhanced, Ag‐surface‐exclusive circular dichroism (CD) band in the UV region. The observed unusual, strong CD response in the hybrid Au@Ag–cysteine system can be used to probe in real time conformational evolution and structural rearrangement of biomolecules in general and also monitor the interfacial interaction between a metal surface and an adsorbed molecule, opening up the possibility of using Ag nanostructures as promising stereochemically attuned nanosensors. Abstract : Plasmonischer Reporter : Diskrete Au@Ag‐Kern‐Schale‐Nanowürfel, die mit Cysteinmolekülen bedeckt sind, zeigen zwei bisignate Zirkulardichroismus(CD)‐Resonanzen im UV‐Bereich. Eine gehört zum molekularen elektronischen CD des Cysteins, die andere ist eine induzierte, ungewöhnliche CD‐Bande, die ihren Ursprung in der Bildung helikaler Netzwerke zwischen benachbarten Cysteinmolekülen hat und durch die Interbandabsorption des Ag drastisch verstärkt wird.