Insulin is a very important polypeptide hormone which controls glucose level in blood and it is used for
the treatment of insulin-dependent type I diabetes. The standard analytical methods for insulin detection
include bioassays, immunoassays, and chromatography. These methods are time-consuming and slow and
frequently require derivatizations of insulin with isotopes or fluorogenic labels to increase the sensitivity
and selectivity [1, 2]. Direct and rapid electrochemical insulin detection is therefore very interesting.
Several articles about in vitro electrochemical insulin detection using modified common electrodes as a
sensing element have been already reported [2, 3], but no work describing an electrochemical three
electrode sensor especially made for insulin detection have been reported. The aim of our work is to prepare a disposable electrochemical sensor for direct insulin determination in aqueous solutions which
could be also used as a base for intelligent sensors and biosensors [4, 5]. This paper reports on the
fabrication of planar multiwalled carbon nanotubes (MWCNTs) thin layer modified carbon working
electrodes (WE) using standard thick film technology (TFT) suitable for direct voltammetric detection of
insulin. Characterization of fabricated microelectrodes and preliminary results of insulin voltammetric
detection using these electrodes are presented here.