Related Experiment Video
Updated: Jun 19, 2026
07:16
DNAzyme 10-23 - Based Nanomachines for Nucleic Acid Recognition
Published on: February 9, 2024
Valency dependence of polymorphism and polyamorphism in DNA-functionalized nanoparticles
Wei Dai1, Chia Wei Hsu, Francesco Sciortino
1Department of Physics, Wesleyan University, Middletown, Connecticut 06459, USA.
Langmuir : the ACS Journal of Surfaces and Colloids
|October 27, 2009
Summary
DNA-functionalized nanoparticles self-assemble into complex networks. Varying nanoparticle functionality (3-6 DNA strands) controls network structure, leading to distinct amorphous or crystalline phases, including interpenetrating networks and polymorphism.
Area of Science:
- Materials Science
- Nanotechnology
- Physical Chemistry
Background:
- Nanoparticles (NP) functionalized with single-stranded DNA (ssDNA) enable the creation of self-assembled nanomaterials.
- DNA's specific binding properties facilitate controlled NP assembly into networks.
Purpose of the Study:
- To investigate the phase behavior and structure of DNA-functionalized NPs.
- To explore the influence of NP valency (number of attached ssDNA) and strand orientation on self-assembly.
- To understand the formation of complex network structures and distinct thermodynamic phases.
Main Methods:
- Coarse-grained molecular dynamics simulations were employed.
- The model system consisted of NPs functionalized with 3 to 6 short ssDNA strands.
- Phase behavior and structural properties were analyzed as a function of NP functionality and symmetry.
Main Results:
- NP assembly into networks is controlled by the number of attached DNA strands.
- Interpenetrating networks lead to multiple thermodynamically distinct amorphous phases (polyamorphism) for 4- and 5-functionalized NPs.
- 6-functionalized NPs exhibit polymorphism, forming up to six interpenetrating crystalline lattices.
Conclusions:
- The number of DNA strands dictates the complexity of NP self-assembly and resulting network structures.
- Interpenetrating networks are a key mechanism for generating distinct thermodynamic phases in these systems.
- Both symmetric and asymmetric functionalization can lead to complex phase behavior, while high functionality favors crystalline structures.
More Related Videos
Related Concept Videos
01:21Factors Affecting Dissolution: Polymorphism, Amorphism and Pseudopolymorphism
Polymorphism refers to the existence of a drug substance in multiple crystalline forms, known as polymorphs. Recently, this term has been expanded to include solvates (forms containing a solvent), amorphous forms (non-crystalline forms), and desolvated solvates (forms from which the solvent has been removed).
Some polymorphic crystals possess lower aqueous solubility than their amorphous counterparts, leading to incomplete absorption. For instance, the oral suspension of Chloramphenicol, which...
Some polymorphic crystals possess lower aqueous solubility than their amorphous counterparts, leading to incomplete absorption. For instance, the oral suspension of Chloramphenicol, which...
00:43Complexometric Titration: Ligands
Different monodentate and polydentate ligands are used as complexing agents in complexometric titration reactions. The formation of complexes by mono- and bidentate ligands involves two or more intermediate steps, limiting their use as complexing agents. In comparison, polydentate ligands can form complexes with metal ions in a single-step process, facilitating sharper end points. This means polydentate ligands, such as amino carboxylic acid derivatives, are most commonly employed in...
01:19Complexation Equilibria: The Chelate Effect
In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...
00:49Ligand Binding and Linkage
Allosteric proteins have more than one ligand binding site; the binding of a ligand to any of these sites influences the binding of ligands to the other sites. When a protein is allosteric, its binding sites are called coupled or linked. In the case of enzymes, the site that binds to the substrate is known as the active site and the other site is known as the regulatory site. When a ligand binds to the regulatory site, this leads to conformational changes in the protein that can influence the...
02:42Valence Bond Theory
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
01:26Polymer Classification: Stereospecificity
Polymerization generates chiral centers along the entire backbone of a polymer chain. Accordingly, the stereochemistry of the substituent group has a significant effect on polymer properties. Polymers formed from monosubstituted alkene monomers feature chiral carbons at every alternate position in the polymer backbone. Relative to the predominant orientation of substituents at the adjacent chiral carbons, the polymer can exist in three different configurations: isotactic, syndiotactic, and...