Optimal film thickness of rGO/MoS2 @ polyaniline nanosheets of 3D arrays for carcinoembryonic antigen high sensitivity detection

Abstract A three-dimensional array of reduced graphene oxide/MoS2 @ polyaniline-layered nanosheets (denoted as rGO/MoS2 @ PANI) has a novel structure of intercalated MoS2/PANI nanosheets arrays arranged on rGO that can be used as carcinoembryonic antigen (CEA) electrochemical immunosensors (detectors). In this graded nanosheet, the PANI was embedded in the MoS2 interlayer. The MoS2/PANI nanosheets themselves limit volumetric changes when arranged as MoS2/PANI nanosheet arrays on rGO nanosheets to provide tight and sufficient heterogeneity. PANI locates on the interface itself and contains a large amount of –NH2 that can bind many antibodies. Simultaneously, we investigated the optimal amount of aniline to add. We found that these arrays had excellent film thickness and conductivity for improving CEA detection sensitivity. The tested immunosensor achieved sensitive and specific detection of CEA, with a detection limit of 0.3 pg mL−1. Under the optimal conditions, the prepared immunosensor exhibited acceptable reproducibility and selectivity and excellent stability. Satisfactory results of human serum samples indicated the potential application of the immunosensor for clinical monitoring of tumor markers.