A novel solid-state electrochemiluminescence sensor based on a Ru(bpy)32+/nano Sm2O3 modified carbon paste electrode for the determination of l-proline

Abstract

A novel solid-state electrochemiluminescence (ECL) sensor was successfully developed for the determination of L-proline. The ECL signal was generated by a sensitive reaction between Ru(bpy)₃²⁺ and L-proline on a carbon paste electrode (CPE) modified with samarium oxide nanoparticles. The presence of Sm₂O₃ nanoparticles (NPs) in the carbon paste was found to enhance the electrochemiluminescence signal. Under optimized conditions, a linear relationship between the ECL intensity and the concentration of L-proline was observed in the linear range of 1.00 × 10⁻⁹ to 1.65 × 10⁻⁷ mol L⁻¹ (R² = 0.996) with a detection limit of 6.0 × 10⁻¹⁰ mol L⁻¹ (S/N = 3) and a relative standard deviation of 3.3%. The method was sensitive, selective, simple and successfully applied to the analysis of L-proline in human serum and urine samples.