Partitioning and Assembly of Metal Particles and Their Bioconjugates in Aqueous Two-Phase Systems

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• 作者：Marcus R. Helfrich ; Mahnaz El-Kouedi ; Mark R. Etherton ; and Christine D. Keating
• 刊名：Langmuir
• 出版年：2005
• 出版时间：August 30, 2005
• 年：2005
• 卷：21
• 期：18
• 页码：8478 - 8486
• 全文大小：538K
• 年卷期：v.21,no.18(August 30, 2005)
• ISSN：1520-5827

文摘

The behavior of metal nanospheres and nanowires and their bioconjugates in aqueous two-phase systems(ATPS) is described. The ATPS used in this work comprised poly(ethylene glycol) (PEG), dextran, andwater or aqueous buffer. Au and Ag nanospheres less than 100 nm in diameter partition between thePEG-rich and dextran-rich phases on the basis of their surface chemistry and can be separated on thisbasis. Larger Au nanospheres and wires accumulate at the interface between the two aqueous phases. Theinfluence of polymer molecular weight and concentration on interfacial assembly of Au wires is described.DNA-derivatized nanowires at the aqueous/aqueous interface retain the ability to selectively bind tofluorescent complementary DNA. In addition, Au nanoparticles have been bound to Au wires via selectiveDNA hybridization at the ATPS interface. Transmission electron microscopy and thermal denaturationexperiments confirm that DNA-driven assembly is responsible for the formation of the nanosphere/wireassemblies. These results demonstrate the biocompatibility of the two-phase interface and point to futureuse as scaffolding in biorecognition-driven assembly.