(706c) DNA-Controlled Brightening of Carbon Nanotube Photoluminescence in Acidic Environments

Single-wall carbon nanotubes (SWCNTs) are a family of one-dimensional (1D) nanostructures that have defined handedness and helicity. Each of the distinct structures of SWCNTs possess unique optical and electronic properties, which are sensitive to small perturbations in the nanotube environment. In this work, we investigated the dispersion stability and optical modulation of DNA-wrapped SWCNTs (DNA-SWCNTs) in aqueous environments for a broad pH range of 2.0-13.0. The stock dispersions of DNA-SWCNTs prepared by our standard preparation method showed near neutral pH values. Surprisingly, by adding hydrochloric acid, an increase in SWCNT fluorescence was observed in acidic environments with pH values around 3.0-5.0. The brightening of nanotube photoluminescence was examined to be strongly dependent on the DNA-sequence among other factors. These results will enable identifying stable DNA-SWCNT hybrids that are suitable for potential applications, including nanotube-based pH sensors.