Highly sensitive electrochemiluminescence detection of mucin1 based on V2O5 nanospheres as peroxidase mimetics to catalyze H2O2 for signal amplification

Here, an electrochemiluminescence (ECL) aptasensor was proposed for the detection of mucin1 (MUC1) using V2O5 nanospheres as peroxidase mimics and MUC1-aptamer binding triggered catalyzed hairpin assembly (CHA) for signal amplification. In this approach, V2O5 nanospheres were capable of immobilizing a large quantity of N-(4-aminobutyl)-N-(ethylisoluminol) (ABEI) functionalized silver nanoparticles (Ag-ABEI) to form the Ag-ABEI@V2O5 signal probe for its large specific surface areas and good stability. Moreover, V2O5 nanospheres not only overcame the intrinsic limitations of natural enzymes, but also could effectively catalyze H2O2 decomposition to generate superoxide anion (O-2(center dot)) for significantly enhancing the ECL intensity of ABEI. To further improve the sensitivity of the proposed aptasensor, the MUC1-aptamer binding triggered CHA was applied to achieve the direct protein recycling without the need of enzyme cleavage and polymerization. The developed approach displayed desirable dynamic range from 10 fg mL(-1) to 10 ng mL(-1) and the limit of detection down to 3.33 fg mL(-1). Furthermore, the described approach showed excellent sensitivity for MUC1 detection with the assistance of V2O5 peroxidase mimics and enzyme-free CHA, indicating that the approach would hold potential applications in biological fields. (C) 2018 Elsevier B.V. All rights reserved.