Enrichment of (6,5) single wall carbon nanotubes using genomic DNA

Single wall carbon nanotubes (SWNTs) have attracted attention because of their potential in a vast range of applications, including transistors and sensors. However, immense technological importance lies in enhancing the purity and homogeneity of SWNTs with respect to their chirality for real-world electronic applications. In order to achieve optimal performance of SWNTs, the diameter, type, and chirality have to be effectively sorted. Any employed strategy for sorting SWNTs has to be scalable, nondestructible, and economical. In this paper, we present a solubilization and chirality enrichment study of commercially available SWNTs using genomic DNA. On the basis of the comparison of the photoluminescence (PL) and near-infrared absorption measurements from the SWNTs dispersed with salmon genomic DNA (SaDNA) and d(GT)20, we show that genomic DNA specifically enriches (6,5) tubes. Circular dichroism and classical all-atom molecular dynamics simulations reveal that the genomic double-stranded SaDNA prefers to interact with (6,5) SWNTs as compared to (10,3) tubes, meanwhile single-stranded d(GT)20 shows no or minimal chirality preference. Our enrichment process demonstrates enrichment of >86% of (6,5) SWNTs from CoMoCat nanotubes using SaDNA.