To showcase the sensitivity of the nanosensors, we first ran the HRP-catalyzed oxidation reaction at PPD concentrations that were below the detection limit of a classical plate reader (Figure -f, Figure ). Along with the fluorescent decrease we observed a blue shift that correlated with the HRP concentration (Figure and g, Figure ). Interestingly, this peak shift seemed to be 5x to 10x times more sensitive than the intensity change. Together with the different equilibrium dynamics, this suggests a complex interplay between the different analytes and the binding sites on the SWCNT surface.