Dual-channel, real-time, long-term stable electrochemical immunosensor based on Au, Cu-vertical graphene for detection of carcinoembryonic antigen in tumor cells

Abstract

Background

The accurate and rapid determination of a broad-spectrum tumor marker, carcinoembryonic antigen (CEA), in tumor cells, human tissues, and body fluids is important for the early diagnosis, drug development, efficacy evaluation, and prognosis tracking of cancer.

Results

In this study, a dual-channel electrochemical immunosensor was designed for the sensitive determination of CEA levels using an Au–AuCu-vertical graphene (VG) sensing platform. An AuCu bimetallic doping strategy was adopted to improve the biocompatibility of graphene with the cells, and Au nanoparticles were electrodeposited to firmly bind numerous CEA antibodies. The immunosensor exhibited a broad limit of linearity from 0.001 to 30000 pg mL⁻¹ and a low limit of detection of 0.28 fg mL⁻¹. This immunosensor exhibited excellent selectivity, reproducibility, and long-term stability. The developed Au–AuCu-VG-based immunosensor pen combined with self-designed electrochemical immunoassay software achieved high-precision real-time on-site analysis of CEA concentrations.

Significance

The proposed AuCu-VG electrode exhibited antibody-binding ability, inherent probe peak, and excellent binding of the Au NPs. A new dual-channel electrochemical immunoassay strategy was developed based on the AuCu-VG electrode, which could sensitively and reliably detect the real-time concentration of CEA released by tumor cells, such as MCF-7.