DNA-Driven Assembly of Bidisperse, Micron-Sized Colloids

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• 作者：Valeria T. Milam ; Amy L. Hiddessen ; John C. Crocker ; David J. Graves ; and Daniel A. Hammer
• 刊名：Langmuir
• 出版年：2003
• 出版时间：November 25, 2003
• 年：2003
• 卷：19
• 期：24
• 页码：10317 - 10323
• 全文大小：516K
• 年卷期：v.19,no.24(November 25, 2003)
• ISSN：1520-5827

文摘

Oligonucleotides are unique chemical moieties that can serve as a useful assembly tool. Unlike mostbioadhesion molecules that bind together with high affinity, the attraction between complementary DNAstrands can vary greatly depending on strand characteristics (e.g., length and sequence choice) and solutionconditions (e.g., ionic strength and temperature). We have studied DNA-mediated assembly of micron-sized, bidisperse mixtures using primarily optical and confocal microscopy. To increase hybridizationefficiency between complementary strands, DNA sequences were designed to have a low self-affinity thatminimizes intrastrand loop and hairpin formations. Single strands of biotinylated DNA were tethered toNeutrAvidin-coated 1.10 and 1.87 micron beads. The resulting oligonucleotide density on the large beadsurface was quantified using flow cytometry. In binary mixtures, we found we could vary the degree ofbinding between complementary beads depending on the number of matching pairs and the ionic strengthof the solution. We have also observed a variety of colloidal structures such as chains of alternating largeand small particles by exploring additional experimental variables such as particle number ratio andvolume fraction.