Effects of Heteropoly Acids and Surfactant on Electrochemiluminescence of Tris(2,2'-Bipyridine) Ruthenium(II)

ABSTRACT

The effects of heteropoly acids and Triton X-100 on electrochemiluminescence (ECL) of Ru(bpy)₃ ²⁺ are investigated. Triton X-100 prevents the oxidation of oxalate and results in an increase of the ECL signal. H₅SiW₁₁VO₄₀ prevents the direct oxidation of oxalate and makes the electrochemical behavior of Ru(bpy)₃ ²⁺ less reversible, which leads to a decrease of the ECL signal. In contrast, H₃PMo₁₂O₄₀ has negligible effect on ECL intensity. Some possible reasons for the effects on the ECL of Ru(bpy)₃ ²⁺ are discussed based on the adsorption of SiW₁₁VO₄₀ ⁵⁻ on electrode surface and the ion association between SiW₁₁VO₄₀ ⁵⁻ and Ru(bpy)₃ ²⁺. The signal of ECL decreases linearly with the concentration of heteropoly acid in the range from 2x10⁻⁶ to 1x10⁻⁴ mol 1⁻¹. The results indicate that ECL of Ru(bpy)₃ ²⁺ is a potential sensitive and selective detection method for heteropoly acids and hence for the elements comprised in them.

Keywords::

• Electrochemiluminescence (ECL)
• tris(2,2'-bipyridine) ruthenium(II)
• heteropoly acids
• Triton X-100