An embodiment provides a method for measuring an analyte component of an aqueous sample, including: introducing an indicator solution to the aqueous sample, wherein the indicator solution comprises a plurality of micelles, wherein an indicator is within the micelles and the plurality of micelles is assembled from a cationic surfactant to form an indicator solution; and measuring an analyte component concentration of the aqueous sample, wherein the measuring comprises measuring a change in fluorescence in the aqueous sample, wherein the change in fluorescence is responsive to the analyte component interacting with the indicator. Other aspects are described and claimed.