Stable Aqueous Nanoparticle Film Assemblies with Covalent and Charged Polymer Linking Networks

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• 作者：Lesley E. Russell ; Anne A. Galyean ; Sherilyn M. Notte ; Michael C. Leopold
• 刊名：Langmuir
• 出版年：2007
• 出版时间：July 3, 2007
• 年：2007
• 卷：23
• 期：14
• 页码：7466 - 7471
• 全文大小：229K
• 年卷期：v.23,no.14(July 3, 2007)
• ISSN：1520-5827

文摘

The construction of highly stable and efficiently assembled multilayer films of purely water soluble gold nanoparticlesis reported. Citrate-stabilized nanoparticles (CS-NPs) of average core diameter of 10 nm are used as templates forstabilization-based exchange reactions with thioctic acid to form more robust aqueous NPs that can be assembled intomultilayer films. The thioctic acid stabilized nanoparticles (TAS-NPs) are networked via covalent and electrostaticlinking systems, employing dithiols and the cationic polymer poly(L-lysine), respectively. Multilayer films of up to150 nm in thickness are successfully grown at biological pH with no observable degradation of the NPs within thefilm. The characteristic surface plasmon band, an optical feature of certain NP film assemblies that can be used toreport the local environment and core spacing within the film, is preserved. Growth dynamics and film stability insolution and in the air are examined, with poly(L-lysine) linked films showing no evidence of aggregation for at least50 days. We believe these films represent a pivotal step toward exploring the potential of aqueous NP film assembliesas a sensing apparatus.