The electrochemical oxidation of picomolar insulin in physiological
buffer solutions was successfully performed using glassy
carbon electrode modified with nickel oxide nanoparticles and guanine.
Due to catalytic activity of guanine and its oxidation products
and antifouling properties of nickel oxide, the guanine/NiOxmodified
GC electrode exhibits greater electrocatalytic activity and
excellent antifouling property toward oxidation of insulin compared
to the individual nickel oxide or guanine coated electrodes
at physiological pH. The modified electrode was prepared using
simple preparation technique without using any specific reagent.
Remarkable electrocatalytic activity and stable response of the
modified electrode at physiological buffer solutions are comparable
with all other modified electrodes employed as an insulin
sensor. In addition to excellent electrochemical performance of