Organizing 6, 5-Carbon nanotubes on DNA origami arrays

Carbon nanotubes1 are cylindrical carbon molecules and can be considered to be composed of one atom thick sheets of carbon called graphene. They have been at the forefront of nanochemistry due to their strength and multiple properties such as absorption, fluorescence, semiconduction, and light scattering capability. DNA Origami (DO)2 has emerged as a novel domain for molecular design, resulting in the generation of numerous one, two, and three-dimensional structures that have provided platforms for the organization of organic species and inorganic nanoparticles through simple modifications. The use of DNA Origami to control the placement of single walled carbon nanotubes (SWCNT) with precise alignment,3 purity and length would be a significant advance in controlled nanoscale organization.4 G-quadruplex (G4) secondary structures are guanine rich ssDNA sequences which fold to create square planar guanine tetrads.5 When G4 is introduced to Hemin, a (G4)/hemin-based DNA enzyme (DNAzyme) self assembles and possesses horseradish peroxidase (HRP)-mimicking catalytic properties.6 In this work, multiple approaches for the immobilization of SWCNTs at precisely designated locations on cross shaped DNA origami7 were implemented, and the results interpreted

Developing Luminescent Lanthanide Coordination Polymers and Metal-Organic Frameworks for Bioimaging Applications

This study focuses on the solvothermal synthesis of two lanthanide-based coordination polymer/metal-organic framework systems assembled from 1,3,5-benzenetricarboxylic acid (BTC) in the nano-sized regime for use as bioimaging agents. These materials were synthesized using two different lanthanide ions, a luminescent center (Eu, Tb) for optical imaging purposes and Gd, whose magnetic properties are particularly beneficial in magnetic resonance imaging (MRI) asa contrast agent. Together, these two features allow for multimodal imaging, useful in the study and diagnosis of disease. Under identical reaction conditions, two different compounds were formed upon changing the identity of the optically active lanthanide metal ion. Compound 1 ([EuGd(BTC)2(H2O)12]) emerged as a one dimensional coordination polymer, increasing in size with reaction time; while compound 2 ([TbGd(BTC)2(H2O)2]n•2DMF) emerged as a three dimensionalframework, decreasing in size with time. Both compounds displayed vibrant luminescence upon UV excitation, indicating potential as bioimaging agents