12th International Symposium on Bioluminescence & Chemiluminescence

Symposium abstracts:

Electrogenerated chemiluminescence behaviors of Ru(bpy)₃²⁺ system on a paraffin-impregnated graphite electrode and a glassy carbon electrode

Feng Li, Hua Cui, Xiangqin Lin

Department of Chemistry, University of Science and Technology of China, Hefei, Anhui 230026, People’s Republic of China.

Email: hcui@ustc.edu.cn; xqlin@ustc.edu.cn

The electrogenerated chemiluminescence (ECL) behaviors of Ru(bpy)₃²⁺ system on a paraffin-impregnated graphite electrode (PIGE) and a glassy carbon electrode (GCE) were studied by using different electrochemical techniques. Under conventional cyclic voltammetric (CV) condition, two anodic ECL peaks (EP1 and EP2) were observed, for PIGE at 1.18 V and 1.37 V, for GCE at 1.23 V and 1.44 V, respectively. The EP1 always occurred. However, it seems that pre-anodization of the electrode surfaces was necessary for the formulation of EP2. The charging current on PIGE was much smaller than that on GCE. The detection limit as low as 1´ 10^-9 mol/L can be reached for the detection of C₂O₄^2- on PIGE by the CV-ECL method at scan rate of 100 mV/s. Strong ECL between Ru(bpy)₃³⁺/Ru(bpy)₃⁺ in a (1:1) CH₃CN / H₂O solution was found on both electrodes as square wave voltammetry (SWV) technique between +1.82V and -1.65V(vs. SCE) (n=10) was used However, GCE showed higher reproducibility than PIGE for continuous SWV measurements. Chronoamperometry was also applied by using a potential step from 0.15 to 1.85 V. The response time took 389 ms on PIGE and 837 ms on GCE to reach a similar ECL maximal intensity for the Ru(bpy)₃²⁺/C₂O₄^2- system. Therefore, GCE can provide high reproducibility and stability, whereas the low-cost PIGE exhibits fast ECL-responsibility and excellent sensitivity.

This is a preprint of an article accepted for publication in Luminescence: Copyright 2001 John
Wiley & Sons, Ltd (Wiley website)