In this study, a carbon paste electrode modified with carbon nanotubes and 5-amino-3',4'-dimethyl-biphenyl-2-ol (5ADB) was used to prepare a novel electrochemical sensor. The objective of this novel electrode modification was to seek new electrochemical performances for the detection of isoproterenol (IP) in the presence of acetaminophen (AC) and N-acetylcysteine (NAC). The peak potentials recorded in a phosphate buffer solution (PBS) of pH 7.0 were 265, 445 and 950 mV vs. Ag/AgCl/KCl (3.0 M) for IP, AC and NAC, respectively. Under the optimum pH of 7.0, the oxidation of IP occurred at a potential about 215 mV less positive than that of the unmodified CPE. The response of catalytic current with IP concentration showed a linear relation in the range from 4.0 x 10(-7) to 9.0 x 10(-4) M with a detection limit of 2.0 x 10(-7) M. (C) 2012 Elsevier Ltd. All rights reserved.