Bypassing the Limitations of Classical Chemical Purification with DNA-Programmable Nanoparticle Recrystallization

摘要

Crystallization is a common and invaluable tool in chemistry for obtaining compounds with a high degree of purity. In a mixture of two or more species, conditions are found in which the desired component is able to selectively form a crystalline structure that excludes impurity species which are unable to incorporate into the ordered lattice formed by the product. This process has been used to purify myriad organic molecules, resolve racemic mixtures with chiral additives, and even separate complex protein mixtures to arrive at samples of maximum homogeneity. Without such tools to obtain materials that are uniform in their structure, function, and composition, elucidation of their chemical and physical properties would be extremely challenging and, in some cases, impossible. Interestingly, a host of anisotropic nanoparticle syntheses currently suffer from an analogous problem as the aforementioned molecular systems—the presence of impurity nanostructures with disparate shapes that obviate a variety of measurements, confound data analysis, and preclude potential applications. Surprisingly few separation methods exist for addressing this challenge and it has been shown that conventional methods for crystallizing nanoparticles based on drying effects or capillary forces are not effective at separating differently shaped nanoparticles.