Voltammetry, chronoamperometry, scanning electrochemical microscopy and electrochemical impedance spectroscopy methods are used for characterization of a glassy carbon electrode modified with multi-walled carbon nanotubes (MWCNTs)-cobalt tetraaminophthalocyanine (CoTAPc) mixture or sequential drop dry modification technique whereby the MWCNTs are first placed on to the electrode followed by CoTAPc. The sequential drop dry CoTAPc-MWCNTs modified surface gave better catalytic responses with a catalytic rate constant of 2.2 x 10(5) M-1 s(-1), apparent electron transfer rate constant of 0.073 cm s(-1), and a limit of detection of 2.8 x 10(-7) M. Scanning electrochemical microscopy (SECM) surface characterization (topography and reactivity) further gave proof the better catalytic perfomance of the sequential drop dry CoTAPc-MWCNTs modified surface. (C) 2013 Elsevier Ltd. All rights reserved.