Dye self-organization in doped silica nanoparticles increases the electrochemiluminescence emission in magnetic bead-based assays

Abstract

We have investigated the effect of dye distribution on the electrochemiluminescence (ECL) intensity measured with a simplified magnetic bead-based immunoassay for two families of silica nanoparticles (NPs) doped with the cationic Ru(bpy)₃²⁺ and the zwitterionic Ru(bpy)₂bps complexes (bps = bathophenanthroline disulfonate). The NPs doped with the Ru(bpy)₂bps complex, which can efficiently self-organize in the NP volume favoring ECL generation, resulted in 150–400% signal enhancement compared to the Ru(bpy)₃²⁺-doped ones.