Next, binding affinities of G d -SWCNTs were compared to pristine sensors. For this purpose, dopamine dose-response curves for pristine, low-and high-defect SWCNTs were recorded (Figure ). Pristine SWCNTs reached saturation at a concentration of 10 µM with a maximum fluorescence increase of 129 %, whereas G d -SWCNTs already saturated at 1 µM dopamine. The lower saturation is also reflected in a slightly different KD value obtained from the sigmoidal fit.