Electrochemiluminescence of the [Ru(bpy)₃]²⁺ Complex: The Coreactant Effect of PAMAM Dendrimers in an Aqueous Medium

Abstract

Electrogenerated chemiluminescence (ECL) from aqueous solutions of tris(2,2'-bipyridine)ruthenium(II), [Ru(bpy)(3)](2+), in the presence of PAMAM G1.5 and G4.5 dendrimers, was observed without the addition of coreactants. The ECL efficiency, Φ(ECL), was enhanced with the addition of increasing amounts of G1.5 dendrimer. Indeed, the ECL efficiency for the [Ru(bpy)(3)](2+)/G1.5 dendrimer became about 10 times higher than that for the [Ru(bpy)(3)](2+)/ oxalate anion system. However, the ECL efficiency in the presence of the G4.5 dendrimer was smaller than that for the G1.5 dendrimer at concentrations similar to those for G1.5 with identical medium conditions. Besides, the addition of NaCl at a given concentration of G1.5 dendrimer decreased the ECL efficiency. The results of Φ(ECL) were interpreted by taking into account the coreactant effect and the electrostatic (long-range and short-range) interactions between the ruthenium(II) complex and the electric field of the dendrimer surface. Standard formal potentials of the [Ru(bpy)(3)](3+/2+) couple in the presence of G1.5 and G4.5 dendrimers were also determined.

Electrochemiluminescence of Water‐Soluble Poly(amidoamine) Dendrimers Conjugated with Multiple Ru(II) Tris(bipyridine) Moieties

“…Perez‐Tejeda et al. observed that PAMAM dendrimers (specifically, generation 1.0, 1.5, 2.0, 4.0 and 4.5 dendrimers) behaved as co‐reactants for the generation of ECL with [Ru(bpy) 3 ] 2+ . Indeed, as shown in Figure a, we also observed the co‐reactant effect of G n ‐NH 2 ( n =2, 4, and 6) dendrimers for the ECL of [Ru(bpy) 3 ] 2+ .…”

Ultrasensitive Apurinic/Apyrimidinic Endonuclease 1 Immunosensing Based on Self-Enhanced Electrochemiluminescence of a Ru(II) Complex

“…13 −15 The Perez-Tejeda's group achieved the enhancement of ECL efficiency of Ru(bpy) 3 2+ using the PAMAM G1.5 dendrimers as coreactant. 16 Tang et al have developed a DNA sensor with adding tripropylamine (TPA) into working buffer solution as a coreactant. 17 In our previous work, we have prepared the apoferritin-templated poly(ethylenimine) (PEI) nanoparticles as labels based on in situ releasing the coreactant of PEI to develop a sensitive ECL immunosensor.…”

Tris(2,2’‐bipyridyl)ruthenium(II)‐Nanomaterial Co‐Reactant Electrochemiluminescence

“…constructed a novel self‐enhanced ECL probes Ru‐NCDs with strong and stable ECL emission comparable to Ru(bpy) 3 2+ /TPA system. In addition to nanomaterials mentioned, PEI and PAMAM dendrimer with a plenty of inherent amine groups were used as excellent alternates for developing self‐enhanced Ru(bpy) 3 2+ ECL nanotags . For instance, Yuan et al .…”

“…In addition to nanomaterials mentioned, PEI and PAMAM dendrimer with a plenty of inherent amine groups were used as excellent alternates for developing self-enhanced Ru(bpy) 3 2 + ECL nanotags. [35][36][37][38] For instance, Yuan et al [37] synthesized coil-like nanocomposites with self-enhanced ECL activity by using Ru(II) complex as ECL emitter, PEI as both co-reactant and scaffold for covalent immobilization of Ru(II) complex, and carbon nanotubes as nanocarriers for the Ru (II)-PEI complex ( Figure 3). The coupling of the intramolecular co-reactant interaction and the multiplication of Ru(II) complex and amine groups in each nanoparticles endow the as-synthesized nanocomposites with high ECL emission quantum yields.…”