Hierarchical Ti3C2 MXene-derived sodium titanate nanoribbons/PEDOT for signal amplified electrochemical immunoassay of prostate specific antigen

Two-dimensional (2D) MXenes have emerged as an attractive platform to construct electrochemical biosensors because of their excellent electronic properties. However, the self-restacking and agglomeration of MXenes lead to unsatisfactory performance. To overcome these drawbacks, herein, the treatment of Ti3C2 MXene through a simultaneous oxidation and alkalization progress was proposed for the synthesis of 3D sodium titanate nanoribbons (M-NTO). Furthermore, conductive poly(3,4-ethyl-enedioxythiophene) (PEDOT) was anchored on 3D M-NTO to enhance its conductivity. The resulting M-NTO-PEDOT composite possessed high specific surface area, fast electron transfer ability, as well as excellent biocompatibility. Subsequently, Au nanoparticles (AuNPs) were electrodeposited on the surface of M-NTO-PEDOT for prostate specific antigen (PSA) antibodies immobilization. Thus, a facile electrochemical label-free immunosensor for sensitive detection of PSA was fabricated on a basis of AuNPs/M-NTO-PEDOT composite. Benefitting from the synergistic effects of M-NTO, PEDOT and AuNPs, the fabricated M-NTO-PEDOT based immunosensor exhibited good analytical performance with a low limit of detection (LOD) of 0.03 pg L-1 (S/N = 3). Additionally, high stability, good selectivity and recovery were achieved in the process of PSA detection in human serum samples.