An enhanced electrochemiluminescence sensor modified with a Ru(bpy) 3 2+ /Yb 2 O 3 nanoparticle/nafion composite for the analysis of methadone samples.

The sensitive interaction between Ru(bpy)3 2+ 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 Yb2 O3- containing modified carbon paste electrode. The presence of Yb2 O3 nanoparticles in the structure of the electrode, was found to enhance its sensitizing effect towards the Ru(bpy)3 2+ -methadone electrochemiluminescence system. The electrodes with the optimal make-up revealed a linear ECL-concentration behavior from 5×10-9 -3×10-7 M and reached method detection limit as low as 2.1×10-10 M 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.