Determination of melamine based on electrochemiluminescence of Ru(bpy)32+ at bare and single-wall carbon nanotube modified glassy carbon electrodes

Abstract

The electrochemiluminescence (ECL) of Ru(bpy)₃²⁺ at bare and single-wall carbon nanotube (SWNT) modified glassy carbon (GC) electrodes has been employed for the determination of melamine for the first time, giving a linear response (R² = 0.99682) for melamine concentration from 1.0 × 10⁻¹⁰ to 1.0 × 10⁻⁵ M at a bare GC electrode in pH 10 borate buffer, and the detection limit is 1.0 × 10⁻¹⁰ M. However, the detection limit can be reduced further to 1.0 × 10⁻¹³ M after modification of the GC electrode by SWNTs. This is much lower compared to other detection methods. The proposed method was applied to the determination of melamine added to a commercial milk sample; the recovery is quite satisfactory with good reproducibility and stability. All of these results provide the possibility of developing a novel ECL detection method for melamine.