AuCu_xO-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 was fabricated based on Au NP-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 the reaction to expose enormous active sites. Also, AuCuxO@m-CeO2 was applied as a matrix to immobilize antibodies by forming bridged bonds between m-CeO2 and carboxyl functional groups of antibodies without additional agents. Furthermore, AuCuxO with prominent catalytic activities dramatically improved the performance of the fabricated immunosensor. Also, the morphology, structure, and electronic state of the surface were characterized by SEM, XRD, TEM, and XPS. In addition, the 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.