Resonance Rayleigh scattering detection of the epidermal growth factor receptor based on an aptamer-functionalized gold-nanoparticle probe

In this study, gold nanoparticles (AuNPs) were modified by the epidermal growth factor receptor (EGFR) aptamer (Apt) to obtain a functionalized Apt–AuNP nanoconjugate probe. The binding of the EGFR to the Apt–AuNP probe resulted in a remarkable enhancement of resonance Rayleigh scattering (RRS). The scattering enhancement (ΔI) is linear to the EGFR concentration in the range of 30–110 ng mL−1 with a limit of detection of 0.7 ng mL−1. The applicability of the developed method in the detection of the EGFR in esophageal cancer cell lysates and human serum samples was tested. The mechanism of selectivity and the reasons for RRS enhancement have been discussed. The prepared Apt–AuNP probe could offer a simple and rapid way to specifically recognize and sensitively determine the EGFR, and would have potential for application in cancer diagnosis and target therapy aimed at this receptor.