New Insights into the Guanine Functionalization of ssDNA-Coated SWCNTs

Abstract

Single-walled carbon nanotubes (SWCNTs) are a class of nanomaterials that due to their unique physical and chemical properties hold great promise for use in future nanoelectronics, engineered smart materials, and biomedical applications. The discovery of the guanine functionalization reaction1 that allows for tailored band gap modulation of carbon nanotubes has sparked interest in prospects for new applications and improved photophysical insights.In this work, we build upon knowledge gained by previous studies of guanine functionalization to use this reaction as a tool to better understand the nature of these hybrids. Using sorted samples, we analyze E11 spectral shapes of band-gap modified SWCNTs to infer single-site exciton perturbations. These results are correlated with Raman spectra to estimate the fraction of guanine sites that become covalently bonded. Further information is obtained from experimental studies of ionic strength dependence and molecular dynamics simulations of ssDNA-wrapped SWCNT structures prior to guanine functionalization.(1) Zheng, Y.; Bachilo, S. M.; Weisman, R. B. Controlled Patterning of Carbon Nanotube Energy Levels by Covalent DNA Functionalization. ACS Nano 2019. https://doi.org/10.1021/acsnano.9b03488.