The fluorescence spectrum and time trace for an individual (6,5) SWNT that was brightened with DTT are displayed in Figure 4. The narrow line width and Lorentzian line shape in Figure 4a are hallmarks of individual SWNT fluorescence spectra. The time trace (temporal evolution of fluorescence intensity) in Figure 4b confirms the nonblinking nature of individual SWNT fluorescence.(2) Furthermore, the high signal-to-noise for these bright SWNTs allowed for confirmation of the nonblinking nature of nanotube fluorescence down to the 10 ms time scale. Altogether, these experiments verify that the fluorescence brightening cannot be attributed simply to shortening or removal of any long-lived blinking “off” periods, but instead, the enhancement is caused by an overall increase in the brightness of SWNT emission.