In this Account, we describe developments in the emerging field of dynamic NP assemblies, which are spontaneously form superstructures containing more than two inorganic nanoscale particles that display the ability to change their geometrical, physical, chemical, and other attributes. In many ways, dynamic assemblies ran represent a bottleneck in the “”bottom-up”" fabrication of NP-based Axitinib molecular weight devices bemuse they can produce a much greater variety Inhibitors,Modulators,Libraries of assemblies, but they also provide a convenient tool for variation of geometries and dimensions of nanoparticle assemblies.
Superstructures of NPs (and those held together by similar intrinsic forces)are classified into two groups: Class 1 where media and external fields can alter shape, conformation, and order of stable super structures with a nearly constant number of NPs or Class 2 where the total number of NPs changes, while the organizational Inhibitors,Modulators,Libraries motif in the final superstructure remains the same.
The future development Inhibitors,Modulators,Libraries of successful dynamic assemblies requires understanding the equilibrium Inhibitors,Modulators,Libraries in dynamic NP systems. The dynamic nature of Class 1 assemblies is associated with the equilibrium between different conformations of a superstructure and is comparable to the isomerization in classical chemistry. Class 2 assemblies involve the formation or breakage of linkages between the NPs, which is analogous to the classical chemical equilibrium for the formation of a molecule from atoms.
Finer classification of NP assemblies in accord with established conventions in the field may include different size Brefeldin_A dimensionalities: discrete assemblies (artificial molecules) and one-dimensional (spaced chains), two-dimensional (sheets), and three-dimensional (superlattices, twisted structures) assemblies. Notably, these dimensional selleck chemicals llc attributes must be regarded as primarily topological in nature because all of these superstructures can acquire complex three-dimensional shapes.
We discuss three primary strategies used to prepare NP superstructures: (1) anisotropy-based assemblies utilizing either intrinsic force field anisotropy around NPs or external anisotropy associated with templates or applied fields, (2) assembly methods utilizing uniform NPs with isotropic interactions, and (3) methods based on mutual recognition of biomolecules, such as DNA and antigen antibody interactions.
We consider optical, electronic, and magnetic properties of dynamic superstructures, focusing primarily on multiparticle effects in NP superstructures as represented by surface plasmon resonance, NP-NP charge transport, and multibody magnetization. Unique properties of NP superstructures are being applied to biosensing, drug delivery, and nanoelectronics.