A Sensitive Surface-Plasmon-Resonance (SPR)-Immunosensor Based on Multilayers of Graphene Oxide and Gold Nanoparticles for Epidermal Growth Factor Receptor Detection

In the last two decades, the use of biosensors, especially in medical sciences, has received increasing attention. In this study, we presented a novel surface-plasmon-resonance (SPR)-based optical biosensor that can be applied for the sensitive detection of epidermal growth factor receptor (EGFR). For the construction of this immunosensor, an anti-human EGFR monoclonal antibody (anti-EGFR mAb) was immobilized on a modified glassy slide with gold nanoparticles (AuNPs) followed by four layers of graphene oxide [(GO)4]. The fabricated sensor consisting of (EGFR/AbEGFR/(GO)4/AuNPs/glassy slide) was evaluated by spectroscopy. Following the attachment of the target protein with Ab (EGFR/Ab/(GO)4/AuNPs/glassy slide), the SPR signal of AuNPs is recorded and used as an analytical signal for quantifying EGFR. The relationship between EGFR concentration and relative absorbance is linear within the range of 0–100 pg/mL, with a detection limit of 0.65 pg/mL. The immunosensor performed well in terms of sensitivity, selectivity, stability, and reproducibility, and it was shown to be appropriate for measuring EGFR directly in human blood samples.