An electrochemical biosensor for the assay of alpha-fetoprotein-L3 with practical applications

The detection of alpha-fetoprotein-L3 (AFP-L3) is of great importance for hepatocellular carcinoma (HCC) diagnosis, but remains unsatisfactory owing to poor sensitivity and complex operating steps. In this work, a simple and sensitive method has been proposed for the detection of AFP-L3. Firstly, biotinylated Lens culinaris agglutinin-integrated silver nanoparticles (B-LCA-AgNPs) is fabricated. Owing to the specific interaction between Lens culinaris agglutinin and AFP-L3, AFP-L3 can be detected directly through the electrochemical signal readout of AgNPs, avoiding separated steps used in clinical practice. Furthermore, after the recognition between B-LCA-AgNPs and AFP-L3, large amount of AgNPs can be gathered at the binding site through avidin-biotin interactions, which can amplify the signal. Therefore, detection of AFP-L3 can be sensitively achieved. Moreover, compared with the other approaches, this new method has a better linear correlation (25-15,000 pg/mL) and a lower detection limit (12 pg/mL). Also, the new method developed in this work has been demonstrated to have good stability and reproducibility for the assay of AFP-L3 in human serum samples, so, it may hold a great application prospect in clinical diagnostics.