Enzymatically Controlled Vacancies in Nanoparticle Crystals*

The nanoparticle crystals can be dynamically changed through the selective and enzymatic hydrolysis of the RNA bonding elements, resulting in superlattices that retain their crystalline structure and habit, while incorporating up to 35% random vacancies generated from the nanoparticles removed. The programmable nature of oligonucleotides allows for an exploration of how nanoparticle atoms crystallize when they have two different types of nanoscale bonds. In this chapter, the authors design a system consisting of three types of gold nanoparticles, with two different types of bonding elements. Specifically, particle A has exclusively DNA bonding elements and is capable of recognizing particles with complementary DNA or RNA. Particle B has pure DNA bonding elements, and particle B' has pure RNA bonding elements, which are complementary to the bonding elements in particle A. Particles A, B, and B' are assembled to form body-centered cubic crystals, and the amount of bonding involving RNA can be controlled by changing the ratio of B to B'.