Functionalization of poly(o-phenylenediamine) with gold nanoparticles as a label-free immunoassay platform for the detection of human enterovirus 71

The detection of human enterovirus 71 (EV 71), an important etiological agent of foot, hand and mouth disease, by a hybrid voltammetric immunosensor was proposed in this paper for the first time. Poly(o-phenylenediamine) (PoPD) film was formed on a glassy carbon electrode (GCE) by utilizing electropolymerization, which yielded an interface with amino groups for the subsequent assembly of gold nanoparticles (AuNPs). The electrochemical characteristics of the immunosensor were investigated by cyclic voltammetry (CV). The parameters influencing the performance of the resulting immunosensor were studied in detail. The current response of the proposed immunosensor decreased linearly in the EV 71 concentration range from 0.1 to 80 ng mL−1 with a detection limit of 0.04 ng mL−1 (signal-to-noise ratio of 3). Due to its simple preparation, good reproducibility and long-time stability, the proposed voltammetric immunosensor will be promising in the point-of-care diagnostics application of clinical screening of multiple diseases.