Selective, Controllable, and Reversible Aggregation of Polystyrene Latex Microspheres via DNA Hybridization

• Published in: Langmuir 2005-06, Vol.21 (12), p.5562-5569
• Main Authors: Rogers, Phillip H, Michel, Eric, Bauer, Carl A, Vanderet, Stephen, Hansen, Daniel, Roberts, Bradley K, Calvez, Antoine, Crews, Jackson B, Lau, Kwok O, Wood, Alistair, Pine, David J, Schwartz, Peter V
• Format: Article
• Language: English
• Subjects: Base Sequence; Chemistry; Colloidal state and disperse state; Condensed Matter; DNA - chemistry; Exact sciences and technology; General and physical chemistry; Latex - chemistry; Latex - metabolism; Microspheres; Models, Chemical; Molecular Sequence Data; Molecular Structure; Nucleic Acid Hybridization; Physical and chemical studies. Granulometry. Electrokinetic phenomena; Physics; Polystyrenes - chemistry; Polystyrenes - metabolism; Soft Condensed Matter; Surface Properties
• ISSN: 0743-7463; 1520-5827
• DOI: 10.1021/la046790y

The directed three-dimensional self-assembly of microstructures and nanostructures through the selective hybridization of DNA is the focus of great interest toward the fabrication of new materials. Single-stranded DNA is covalently attached to polystyrene latex microspheres. Single-stranded DNA can function as a sequence-selective Velcro by only bonding to another strand of DNA that has a complementary sequence. The attachment of the DNA increases the charge stabilization of the microspheres and allows controllable aggregation of microspheres by hybridization of complementary DNA sequences. In a mixture of microspheres derivatized with different sequences of DNA, microspheres with complementary DNA form aggregates, while microspheres with noncomplementary sequences remain suspended. The process is reversible by heating, with a characteristic “aggregate dissociation temperature” that is predictably dependent on salt concentration, and the evolution of aggregate dissociation with temperature is observed with optical microscopy.