Determination of melamine based on electrochemiluminescence of Ru(bpy)32+ at chemically converted graphene-modified glassy carbon electrode

Abstract

Electrochemiluminescence (ECL) of Ru(bpy)₃²⁺ at chemically converted graphene (CCG)-modified glassy carbon (GC) electrode has been employed for the determination of melamine. It gave a linear response (R² = 0.99) for melamine concentration from 1.0 × 10⁻¹⁵ mol L⁻¹ to 1.0 × 10⁻¹¹ mol L⁻¹ with a remarkable detection limit of 1.0 × 10⁻¹⁵ mol L⁻¹ in 0.1 mol L⁻¹ phosphate buffer (pH = 10). This is much lower compared to other detection methods. To check its applicability, the proposed method was employed for the determination of melamine spiked into the milk samples, and a detection limit of 5.0 × 10⁻¹⁵ mol L⁻¹ was achieved with good reproducibility and stability. All these results provide a possibility to develop an ECL method for the determination of melamine at the chemically converted graphene (CCG)-modified GC electrode.