Enhanced solid-state electrochemiluminescence of Ru(bpy)32+ with nano-CeO2 modified carbon paste electrode and its application in tramadol determination

Abstract

A sensitized solid-state electrochemiluminescence (ECL) was successfully used for the determination of tramadol. The ECL signal was produced by a sensitive Ru(bpy)₃²⁺-tramadol reactions. A modified carbon paste electrode (CPE) was applied as a working electrode. Incorporation of cerium oxide nanoparticles in the carbon paste led to the fabrication of a novel ECL sensor. CeO₂ showed attractive sensitizing effect on Ru(bpy)₃²⁺-tramadol electrochemiluminescence system. Under the optimal conditions for Ru(bpy)₃²⁺-tramadol system, a linear relationship between the ECL intensity and concentration of tramadol in the range of 1.0 × 10⁻¹⁰ to 2.5 × 10⁻⁸ mol L⁻¹ was obtained with detection limit of 9.0 × 10⁻¹¹ mol L⁻¹ and relative standard deviation of 2.9% (S/N = 3). The method is sensitive, selective, and simple and has been successfully applied for the determination of tramadol in human serum, urine and pharmaceutical formulation.