AuCuxO-Embedded Mesoporous CeO2 Nanocomposites as a Signal Probe for Electrochemical Sensitive Detection of Amyloid-Beta Protein

A sandwich-type electrochemical immunosensor for detecting Amyloid-beta protein (Aβ) was fabricated based on Au NPs functionalized reduced graphene oxide (Au@rGO) as an effective sensing platform and AuCuxO embedded mesoporous CeO2 (AuCuxO@m-CeO2) nanocomposites as the catalytic matrix. The AuCuxO@m-CeO2 composites were obtained by adjusting the amount of m-CeO2 in reaction to expose enormous active sites. And AuCuxO@m-CeO2 can be implemented as a matrix for immobilizing secondary antibody by forming bridged bonds between m-CeO2 and carboxyl functional groups of antibody without additional agents. Furthermore, AuCuxO with prominent catalytic activities dramatically improved the performance of the fabricated immunosensor. And the morphology, structure, and electronic state of the surface were characterized by SEM, XRD, TEM, and XPS. In addition, the proposed immunosensor demonstrated a wide linear range of 100 fg mL-1 to 10 ng mL-1. This study may provide a way for sensitively detecting various biomarkers.