Highly sensitive ECL immunosensor based on multi-labeling of luminol via a dendrimer on Fe3O4 nanoparticles

Abstract

In this study, a dendrimer was used to multiply immobilize luminol for constructing highly sensitive microalbuminuria (mAlb) electrochemiluminescence (ECL) immunosensor. The composite dendrimer was linked to Fe₃O₄ magnetic nanoparticles by layer-by-layer self-assembly to fabricate a magnetically controlled mAlb immunosensor. The determination of mAlb concentration was realized by competition reactions between mAlb and glucose oxidase-labeled mAlb with anti-mAlb on the dendrimer. MAlb concentrations were determined between 2 and 322 pg mL⁻¹, and the detection limit was 0.084 pg mL⁻¹. The immunosensor proposed in this work was successfully applied to mAlb assay in urine samples.