Adsorption Anodic waves Apparent formation constant Association constant Benesi-Hildebrand Carbon nanotubes Carbon-nanotube modified electrodes Cd complex Complexation Current-controlled Cyclic voltammetry Differential pulse voltammetry Direct method Drug interactions ELectrochemical methods Electrochemical behaviors Electrochemical experiments Electrochemical investigations Electrodes Formation constants Glass membrane electrodes Glassy carbon Glassy carbon electrodes Gold compounds Gold electrodes Host guest interactions Langmuir isotherm Lower detection limit Mangiferin Modified electrodes