A novel and ultrasensitive sandwich-type electrochemical immunosensor based on delaminated MXene@AuNPs as signal amplification for prostate specific antigen (PSA) detection and immunosensor validation

In this study, an ultra-sensitive electrochemical immunosensor for PSA detection was designed. Firstly, gold nanoparticles (AuNPs)/p-aminothiophenol (ATP) functionalized graphene oxide (GO) composite (AuNPs-ATPGO) was constructed and modified to glassy carbon electrode (AuNPs-ATPGO/GCE). AuNPs-ATPGO/GCE was utilized as immunosensor platform to increase the amount of PSA antibody1 (Ab1). After that, self-assembled delaminated MXene-gold nanoparticles (d-Ti3C2TX MXene@AuNPs) was used to label PSA seconder antibody2 (Ab2) as signal amplification. The prepared AuNPs-ATPGO, d-Ti3C2TX MXene@AuNPs and electrochemical immunosensor was charecterized by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), scanning electron microscope (SEM), x-ray diffraction (XRD) method, x-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FTIR). The linearity range and detection limit (LOD) were obtained as 0.01–1.0 pg mL-1 and 3.0 fg mL-1, respectively. © 2020 Elsevier B.V.