Electrochemical platform for simultaneous determination of levodopa, acetaminophen and tyrosine using a graphene and ferrocene modified carbon paste electrode

A carbon paste electrode (CPE) was modified with graphene and ethyl 2-(4-ferrocenyl-[1,2,3]triazol-1-yl) acetate (EFTA) and used for electrocatalytic oxidation of levodopa. Under optimum conditions and at pH 7.0, the oxidation of levodopa occurs at a potential about 280 mV (vs. Ag/AgCl) using square wave voltammetry (SWV) which is less positive than that of an unmodified CPE. The modified electrode can well resolve the voltammetric peaks of levodopa, acetaminophen and tyrosine. The peak current is linear in the 0.2 μM to 0.4 mM levodopa concentration range. The respective figures for acetaminophen and tyrosine are 485 mV and 745 mV, respectively, and the analytical ranges are from 1.0 μM to 0.15 mM for acetaminophen, and from 5.0 μM to 0.18 mM for tyrosine. .