“…Similar to other electrochemical methods [26,27], this method had some overwhelming advantages for characterizing surfactant adsorption at hydrophobic surfaces compared with the nonelectrochemical methods, such as high sensitivity, wide concentration range, easy fabrication and operation, and low cost. In contrast to previous electrochemical methods for characterizing surfactant adsorption at hydrophobic surfaces [26,27], the replacement of the disturbed SAMs of dodecanethiol or a carbon paste electrode surface by the regular SAMs of hexanethiol provided a more ideal hydrophobic surface mode, the replacement of the negatively charged electrochemical probe K 3 Fe(CN) 6 by positively charged MB completely overcame the deficiency of the coprecipitation of K 3 Fe(CN) 6 with positive charged surfactants at high concentrations, and the avoidance of using equivalent circuits significantly simplified the operating procedure in electrochemical impedance spectroscopy (EIS). As a versatile platform, this electrochemical system can be used to monitor the adsorption of various neutral and positively charged surfactants on hydrophobic surfaces.…”