Bead-based assays are successfully combined with electrochemiluminescence (ECL) technology for detection of a wide range of biomarkers. Herein, we demonstrate a novel approach to enhance the ECL signal by decorating micrometric beads with [Ru(bpy)3]2+-grafted microgels (diameter ∼100 nm). Rapid and stable light emission was spatially resolved at the level of single functionalized beads. An enhancement of the ECL signal of microgel-labeled beads by 9-fold was observed in comparison to molecularly linked [Ru(bpy)3]2+ beads prepared by a sandwich immunoassay or an amide bond. Imaging the ECL signal at the single bead level shows that the size of the ECL-emitting layer is extended using the microgels. The reported method offers a great promise for the optimization of bead-based ECL detection and subsequent development of ECL microscopy.
Keywords: Bead-based assays; Electrochemiluminescence; Electrochemistry; Imaging; Microgels.
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