An enhanced electrochemiluminescence sensor modified with a Ru(bpy)₃²⁺/Yb₂O₃ nanoparticle/nafion composite for the...

The sensitive interaction between Ru(bpy)₃²⁺ and methadone was used for the modification of a solid-state electrochemiluminescence electrode, and it was also successfully applied to determine methadone in the samples. The working electrode was made of a Yb₂O_3-containing modified carbon paste electrode. The presence of Yb₂O₃ nanoparticles in the structure of the electrode, was found to enhance its sensitizing effect towards the Ru(bpy)₃²⁺-methadone electrochemiluminescence system. The electrodes with the optimal make-up revealed a linear ECL-concentration behavior from 5×10^-9-3×10^-7M and reached method detection limit as low as 2.1×10^-10M with a relative standard deviation of 4.4% (S/N=3). This modified ECL could present a simple yet sensitive and selective route for the determination of methadone in different samples.