An impedimetric immunosensor for determination of porcine epidemic diarrhea virus based on the nanocomposite consisting of molybdenum disulfide/reduced graphene oxide decorated with gold nanoparticles.

An electrochemical immunosensor for the determination of porcine epidemic diarrhea virus (PEDV) is described. It was manufactured by using gold nanoparticles/molybdenum disulfide/reduced graphene oxide nanocomposites modified on the surface of a glassy carbon electrode (GCE). The independently developed monoclonal antibody of PEDV-2C11 was immobilized on the modified electrode at site of gold nanoparticles provided in the nanocomposites. The concentration of PEDV was quantified by measuring the changes in the charge transfer resistance of the electrode before and after the immunoreaction between antigen-antibody by using hexacyanoferrate(II)/(III) as the redox probe. The frequency range was 10^-1 to 10⁵ Hz at the amplitude of 10 mV and an applied potential of + 0.180 V. Based on the immunoreaction between PEDV antigen and PEDV-2C11 antibody in 0.1 M phosphate buffer containing 0.1 M KCl at 37.5 °C for 140 min, the relative change in impedance was proportional to the logarithmic value of PEDV concentrations in the range of 82.5 to 1.65 × 10⁴ TCID₅₀ mL^-1. Good reproducibility, stability, and specificity of the proposed immunosensor were obtained. It was successfully applied to the determination of PEDV in the spiked sample. Graphical abstractSchematic representation. a The preparation of AuNP/MoS₂/rGO composites. b Representation of modification and functioning of the label-free electrochemical immunosensor and the electrochemical impedimetric response obtained before (a) and after (b) incubation of PEDV.