An efficient label-free immunosensor based on ce-MoS2/AgNR composites and screen-printed electrodes for PSA detection

Abstract

Label-free electrochemical immunosensors (EIs) are simple and sensitive in cancer diagnosis. Electrode materials which can offer a large specific area and excellent electrical conductivity play a critical role in the fabrication of EIs. In our study, ce-MoS2/AgNR composite was synthesized via Van der Waals force and electrostatic interaction between chemical exfoliated MoS2 nanosheets (ce-MoS2) and Ag nanorods (AgNRs). The conductivity of ce-MoS2/AgNR composite was almost three times higher than single ce-MoS2 because of the synergistic effect between ce-MoS2 and AgNRs. Furthermore, AgNRs could effectively inhibit the stacking of MoS2 nanosheets. The EIs for prostate-specific antigen (PSA) detection were fabricated based on ce-MoS2/AgNR composite. The fabricated EIs retained a wide linear response range (0.1–1000 ng/ml), low sensitivity (0.019 μA/(ng ml−1)), and low detection limit (0.051 ng/ml) for the detection of PSA. Therefore, the EIs based on screen-printed electrode (SPE) and ce-MoS2/AgNR composite could be applied to clinical diagnosis of prostatic cancer and have potential application in the detection of other cancer biomarkers.