Electrochemical determination of L-methionine using the electropolymerized film of non-peripheral amine substituted Cu(II) phthalocyanine on glassy carbon electrode.

This paper reports the stable determination of L-methionine (L-Met) in phosphate buffer solution (pH=4.0) using the electropolymerized film of 1,8,15,22-tetraaminophthalocyanato-copper(II) (p-4α-Cu(II)TAPc) on glassy carbon electrode (GCE). Bare GCE shows an ill-defined oxidation wave around 1.32 (±0.02) V for L-Met whereas p-4α-Cu(II)TAPc electrode shows a well-defined oxidation peak at 1.26 (±0.02) V. The modified electrode does not show any fouling effect towards the oxidation of L-Met. Further, the p-4α-Cu(II)TAPc modified electrode was successfully used for the selective determination of L-Met in the presence of ascorbic acid (AA) and uric acid (UA). Differential pulse voltammetry method was used to determine L-Met in the concentration range of 50-500 μM with a detection limit of 2.7×10⁻⁸ M (S/N=3). The present modified electrode shows good recovery results for spiked L-Met in human blood serum sample. Copyright Â