Thermal Exfoliated Graphite/Chitosan Modified Glassy Carbon Electrode for Cu(II) Ion Sensing

Aims: Here, we report a simple strategy for the preparation of thermally exfoliated graphite (EG) and its application to modify glassy carbon electrode (GCE) surfaces for electrochemical Cu²⁺ ion sensing. Method: The electrochemical Cu²⁺ sensor was constructed by a layer modification of a glassy carbon electrode (GCE) with exfoliated graphite (EG) and chitosan (CS) as a binder, and CS also supports a large number of -NH2 functional groups for Cu²⁺ capture. Result: Due to the creation of a three-dimensional (3D) structure, the EG/CS-coated GCE (EG/CS/GCE) electrode exhibited a higher sensitivity towards Cu²⁺ detection than that of modification by graphite/chitosan (GP/CS), chitosan (CS) or graphite intercalated compounds (GIC)/chitosan. Conclusion: The proposed method could detect Cu²⁺ in the range of 10 μM to 3 mM with a detection limit of 0.5 μM and sensitivity of 43.62 μA mM^-1.