Paper-based electrochemiluminescence immunodevice for carcinoembryonic antigen using nanoporous gold-chitosan hybrids and graphene quantum dots functionalized Au@Pt

摘要

A highly sensitive 3D origami device combined with electrochemiluminescence (ECL) immunosensor was introduced for sensitive point-of-care testing of carcinoembryonic antigen (CEA). This immunodevice was developed based on nanoporous gold/chitosan modified paper working electrode (NGC-PWE) as sensor platform and green-luminescent graphene quantum dots (GQDs) functionalized Au@Pt core-shell nanoparticles (GQDs/Au@Pt) as signal label. Firstly, the origami device was fabricated by directly screen-printing electrodes on wax-patterned pure cellulose paper. Secondly, the NGC hybrids were prepared and introduced for binding of primary antibody with high loading amount. The ECL nanoprobe (Ab_2/GQDs/Au@Pt) was designed by covalent assembly of signal antibody (Ab_2) on GQPs tagged Au@Pt core-shell nanoparticles. After a sandwich-type immunoreaction, the GQDs/Au@Pt labels were captured onto the NGC-PWE surface. The amplified ECL signals were achieved by efficient catalysis of the glucose oxidase (GOx) towards the oxidation of glucose to in situ generate H_2O_2 as coreactant and the enhancement of Au@Pt to the ECL reaction of GQPS-H2O2. Under the optimized experimental conditions, the proposed strategy exhibited excellent high sensitivity for the determination of CEA ranging from 1.0 pgmL~(-1) to 10ngmL~(-1) with the detection limit of 0.6 pgmL~(-1). The assay results of CEA in clinical serum samples were in a good agreement with the commercial ECL single-analyte tests. The proposed enhanced ECL immunosensor may become a promising technique for detection of other tumor markers.