DNA-Based Toolkit for Directed Synthesis of Zinc Oxide Nanoparticle Chains and Understanding the Quantum Size Effects in ZnO Nanocrystals

Growth and assembly of inorganic materials with the guidance of biomolecules is a promising route to control over the arrangement of nanoparticles. We present in this article an effective and efficient method for producing zinc oxide (ZnO) nanoparticle chains by directly using DNA as guide. Using extensive experiments over a wide range of synthesis parameters, such as the solvents and the concentrations of reactants, we have obtained high-quality ZnO nanoparticle chains in different sizes. This strategy makes it possible to tailor the optical and structural properties of ZnO nanoparticles aggregated on DNA. We have also studied theoretically the variation of the bandgap energy with the size of the ZnO nanocrystals using a chemical bond theory of quantum size effects. Furthermore, possible mechanisms are discussed in detail.