To further explore and understand the influence of diazonium salts on single SWCNTs, the defect reaction was monitored in real-time in both E11 and E11 * channels (Figure , Supplementary Video S1 and S2). Interestingly, the two spectral contributions were not synchronous as the overall fluorescence intensity (Figure ). The E11 brightness decreased directly with the addition of the diazonium salt, while the E11 * emission slowly increased over time (10 s -200 s). This pattern could be explained by a two-step mechanism : 1) diazonium salt adsorbs on the SWCNT surface and directly quenches the E11 emission.