A new type of "smart" single-walled carbon nanotubes is created by wrapping a pyrene-labeled CO2-responsive polymer via p-p stacking. The polymer/SWNT hybrids not only undergo a hydrophobic-hydrophilic transition upon CO2 stimulus in a mixed solvent, but also exhibit switchable dispersion/aggregation states upon the alternate bubbling of CO2 and N-2 in pure water.