Highly sensitive electrochemiluminescence immunosensor based on ABEI/H₂O₂ system with PFO dots as enhancer for...

In this work, poly[9,9-dioctylfluorenyl-2,7-diyl] (PFO) dots is discovered to display an appealing dual enhancement effect for the electrochemiluminescence (ECL) system of N-(aminobutyl)-N-(ethylisoluminol)/hydrogen peroxide (ABEI/H₂O₂), which not only enhances the ECL intensity of ABEI but also catalyzes decomposition of H₂O₂ to further amplify the ECL signal of ABEI. Owing to the electronegative property of PFO dots, electropositive ABEI-PEI as ECL reagent could be adsorbed on their surface and thus form a novel luminescence emitter (ABEI-PEI-PFO dots) with high ECL efficiency based on electrostatic attraction. Meanwhile, the water solubility and stability of this emitter are improved in virtue of the amine-rich property of ECL reagent (ABEI-PEI), which could increase the luminous efficiency of ECL reaction in aqueous solution. To increase the electron transfer efficiency, Pt nanoparticles (PtNPs) supported on reduced graphene oxide nanosheets (RGOs) via a onepot synthetic strategy are chosen as immobilizing platform for the ECL emitter (ABEI-PEI-PFO dots). Herein, the obtained dual-amplifed ABEI-PEI-PFO dots-RGOs/PtNPs complex is served as an ideal nanocarrier to capture detection antibody (Ab₂). According to sandwiched immunoreaction, a highly sensitive ECL immunosensor is constructed for the detection of kidney injury molecule-1 (KIM-1) with a linearity from 50 fg mL^-1 to 1 ng mL^-1 and a detection limit of 16.7 fg mL^-1. The developed ECL emitter combining dual amplified property for signal enhancement purpose would provide new thought and potential for sensitive bioanalysis and clinical application.