Potential cycling was used for oxidation of chloropromazine and producing an electroactive redox couples which strongly adsorbed on the electrode surface modified with carbon nanotubes and ionic liquid nanocomposite. The modified electrode shows excellent electrocatalytic activity toward NADH oxidation. The differential pulse voltammetry detection provided high sensitivity, 0.5835 A M1, low detection limit, 80 nM at concentration range up to 20 mM. An ethanol biosensor was also developed by immobilizing alcohol dehydrogenase enzyme onto nanocomposite. Differential pulse voltammetric detection of ethanol gives linear responses over the concentration range 40 mM– 1.5 mM with detection limit 5 mM and sensitivity 1.97 mA mM1.