Signal-Enhanced Immunosensor-Based MOF-Derived ZrO₂ Nanomaterials as Electrochemiluminescence Emitter for D-Dimer...

Metal oxide nanomaterials have garnered significant attention in the field of electrochemiluminescence (ECL) sensing due to their efficient, stable, and nontoxic properties. However, the current research on metal oxide nanomaterials has primarily focused on their cathodic luminescence properties, with limited reports on their anodic ECL properties. In this study, we utilized MOF-derived ZrO₂ nanomaterials as luminophores to generate stable anodic ECL signals in the presence of the coreactant tripropylamine (TPrA). Additionally, a signal-enhancing immunosensor was developed to analyze D-dimer by incorporating the coreaction accelerator Cu-doped TiO₂ (TiO₂-Cu). The ZrO₂ synthesized by calcining UiO-67 demonstrated nontoxicity and biocompatibility, exhibiting efficient and stable ECL emission in a TPrA solution. The inclusion of TiO₂-Cu as a coreaction accelerator in the immunosensor resulted in the formation of a ternary system of ZrO₂/TiO₂-Cu/TPrA. The Cu doping effectively narrowed the bandgap of TiO₂ and enhanced its conductivity. As a substrate, TiO₂-Cu reacted with more TPrA, generating sufficient free radicals to effectively enhance the ECL signal of ZrO₂. In this article, a short peptide ligand, NFC (NARKFYKGC), was designed to immobilize antibodies and maintain the activity of antigen-binding sites during the construction of the immunosensor. The developed immunosensor was used for the accurate detection of D-dimers, with a wide linear range of 0.05-600 ng/mL and a low detection limit of 21 pg/mL..