New Insights on Potentiometric Immunosensor at Carbon Fiber Microelectrode for Alpha‐Fetoprotein in Hepatocellular Carcinoma

Abstract

Herein, we investigated the analytical features of potentiometric immunosensors for detection of alphafetoprotein (AFP) in hepatocellular carcinoma at different electrodes, such as carbon fiber microelectrode (CFME) and carbon-disk electrode (CDE), respectively. To construct such an immunosensor, anti-AFP capture antibodies were first conjugated covalently onto the activated electrodes through typical carbodiimide coupling. Thereafter, one-step immunoreaction protocol was successfully introduced to develop a new potentiometric immunoassay upon addition of AFP. Accompanying the antigen-antibody reaction, the surface charges of the modified electrodes were changed for the readout of electric potential. Results indicated that the linear range of CDE-based immunosensor was 0.1-100 ng mL À 1 AFP, whereas the assay sensitivity by using CFME could be further increased to 3.2 pg mL À 1 with the linear range from 0.01 to 500 ng mL À 1 AFP. Meanwhile, CFME-based immunosensor showed high sensitivity, good reproducibility and specificity, and could be utilized for the analysis of human serum specimens with consistent results relative to commercialized ELISA kit.

Biosensing of Alpha-Fetoprotein: A Key Direction toward the Early Detection and Management of Hepatocellular Carcinoma

“…To apply an immunoassay-based sensing technique, Li et al innovatively developed potentiometric immunosensors for the sensitive detection of alpha-fetoprotein (AFP) in hepatocellular carcinoma using distinct electrodes, including a carbon fiber microelectrode (CFME) and carbon-disk electrode (CDE) [70]. The immunosensor construction involved the initial covalent conjugation of anti-AFP capture antibodies onto activated electrodes through typical carbodiimide coupling.…”

The role of nanoparticles in non‐invasive electrochemical immunosensor technology and recent developments

“…Electrodes immobilized with anti-AFP via carbodiimide were used in the potentiometric method. As a result of the selective binding reaction between antigen and antibody, changes in the surface charge of the electrode, and therefore in its electric potential, were determined [32].…”

“…For example, F I G U R E 2 A) Schematic illustrations of potentiometric measurement for AFP. Reprinted (adapted) with permission from [32], B) Conductometric immunosensor with the bimetallic PtPd-amplified and catalytic process. Reprinted (adapted) with permission from [33], C) The electrochemical immunosensor for MCM5 on the gold electrode.…”

Aptamer‐functionalized Ti3C2‐MXene Nanosheets with One‐step Potentiometric Detection of Programmed Death‐ligand 1

“…So, the resulting potentiometric probes have been widely utilized to directly monitor ionic species in complex samples [12][13][14][15]. Recently, Li et al developed a potentiometric immunosensor for the alpha-fetoprotein detection in hepatocellular carcinoma at the carbon fiber microelectrode [16]. Zhou et al investigated the catalytic hairpin assembly-mediated surface charge density on the electrode for potentiometric detection of microRNA-21 in IgA-nephropathy [13].…”