Tuning the wavelength of fluorescent carbon tubes

A research team has studied the fluorescence of carbon nanotubes (CNTs) made from graphene sheets a single atom thick. Various hexagonal organic molecules were bonded to the CNTs’ outer wall. The wavelength of infrared emission from the CNTs could be tuned depending on which elements (e.g., bromine or nitrogen) were attached to the organic molecules, and at which position. Fine-tuning the fluorescence is important for optical and bioimaging applications of CNTs.