Carbohydrate antigen 19-9 electrochemical immunosensor based on 1D-MoS2 nanorods/LiNb3O8 and polyoxometalate-incorporated gold nanoparticles

Abstract

The diagnosis of disease and the monitoring of patient in cancer research are related to biomarkers. Carbohydrate antigen 19-9 (CA 19-9) as the main tumor biomarker is necessary for digestive tract associated cancers. In this study, 1D-MoS2 nanorods/LiNb3O8 (1D-MoS2 NRs/LNO) as signal amplification and polyoxometalate-incorporated gold nanoparticles (AuNPs@POM) as sensor platform were prepared and the electrochemical immunosensor application was conducted based on 1D-MoS2 NRs/LNO and AuNPs@POM for CA 19-9 detection. After the preparation of AuNPs@POM nanocomposite, primer antibody immobilization was conducted via amino-gold affinity between primer antibody and AuNPs@POM nanocomposite. After that, strong pi-pi and electrostatic interactions between seconder antibody and 1D-MoS2 NRs/LNO provided the successful conjugation of seconder antibody. The physicochemical characterizations including scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD) were performed for electrochemical CA 19-9 immunosensor. Furhermore, to asses the electrochemical performance of the immunosensor, cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectrospcopy (EIS) techniques were performed. The quantification limit (LOQ) and the detection limit (LOD) values were obtained as 0.10 mu U mL(-1) and 0.030 mu U mL(-1), respectively. This immunosensor having high selectivity, stability and reusability creates a novel chance for clinical immunoassays.