Label-free electrochemical aptasensor for GPC3 detection based on RGO-CS-Fc/Pt NPs

Abstract

Glypican-3 (GPC3) is a promising biomarker of early detection of hepatocellular carcinoma (HCC). Herein, an label-free electrochemical aptasensor for the detection of GPC3 was developed based on reduced graphene oxide-chitosan-ferrocene/platinum nanoparticles (RGO-CS-Fc/Pt NPs). GPC3 aptamer (GPC3-Apt) was immobilized onto the surface of the modified screen-printed carbon electrode (SPE) by RGO-CS-Fc/Pt NPs. When the GPC3 was added to the platforms of aptasensor, the specific recognition reaction between the GPC3-Apt and GPC3 produced aptamer-antigen complex and arranged on the electrode surface, which made the change of electrochemical signals of Fc obtained by differential pulse voltammetry (DPV). Hence, the calibration graph (peak current vs GPC3 concentration) can be used for quantification of GPC3. The measured peak current and GPC3 concentration have a good linearity in the range of 0.05-10.0 μg/mL, a correlation coefficient of 0.9805 and a low detection limit of 0.018 μg/mL (S/N=3). Moreover, the designed aptasensor showed good performance with excellent selectivity, acceptable reproducibility and stability. Thus, this label-free electrochemical aptasensor has promising applications for the early detection of HCC.