Cobalt-based metal-organic frameworks as co-reaction accelerator for enhancing electrochemiluminescence behavior of N-(aminobutyl)-N-(ethylisoluminol) and ultrasensitive immunosensing of amyloid-β protein

In this work, a luminophore/coreactant/co-reaction accelerator ternary electrochemiluminescence (ECL) system is proposed by using N-(aminobutyl)-N-(ethylisoluminol) (ABEI) functionalized cobalt-based MOFs (Co-MOFs/ABEI) with superior peroxidase-like activities as the luminophore. ABEI, the derivative of luminol, is used as the reductant and organic ligand to synthesize flower-like Co-MOFs/ABEI. The as-synthesized Co-MOFs/ABEI not only function as desirable nano-carriers for the enrichment of ABEI, but also act as co-reaction accelerators for the catalysis of H2O2 decomposition. Furthermore, Au nanoparticles are decorated on Co-MOFs/ABEI via electrostatics attraction, endowing it with favorable biocompatibility and electrocatalytic property to bond with detection antibodies and generate more excited state ABEI*. Besides, with the advantages of large specific surface area and easy preparation, Au nanoparticles functionalized Fe3O4@polypyrrole is utilized to anchor the capture antibodies for immunoaction with target analyze. Amyloid-beta protein (A beta(42)), a principal hallmark of Alzheimer's disease, is chosen as the target analyze. The proposed A beta(42) immunosensor performs with a broad linear range from 10 fg mL(-1) to 100 ng mL(-1) and a detection limit down to 3 fg mL(-1), opens up new prospects for clinical analysis of A beta(42) and provides promising approaches to synthesize luminophore-functionalized MOFs with high luminous efficiency for ECL bioanalysis.