Cost Effective Electrochemical Sensor for L-Methionine Based on Graphitic Carbon Nitride Sheets Modified Electrode

L-methionine (L−Me) deficiency in human body leads to several complications. In the present work, graphitic carbon nitride nanosheets (GCN−S) modified glassy carbon electrode (GC/GCN−S) was developed as a cost effective electrochemical sensor for L−Me. The oxidation of L−Me at bare GC electrode shows an ill-defined peak and it was unstable whereas a well-defined stable oxidation peak was obtained at GC/GCN−S electrode. While increasing L−Me concentration from 100 nM to 0.2 mM, the amperometric current increases linearly with R²=0.9901 and LOD was found to be 0.32 nM (S/N=3). Finally, GC/GCN−S electrode was used to determine L−Me in blood serum samples.