Point‐of‐Care Based Electrochemical Immunoassay for Epstein‐Barr Virus Detection
Miao Yu, Ming Liu, Yuan Li
Abstract
This work describes a label‐free electrochemical immunosensor for the sensing of Epstein‐Barr virus (EBV) with high sensitivity. First, a monolayer of 1,6‐hexanedithiol (HDT) was fabricated on the screen‐printed electrode surface by the interaction between sulfur atoms and SPE. AuNPs can be modified on the electrode by the Au‐S bond formed between the HDT‐free group and Au atom in AuNPs. Protein A is then adsorbed onto AuNPs. Several parameters were optimized. The optimum concentration of protein A is 0.6 mg/mL. The optimum immobilization time for protein A is 90 min. The optimum concentration of antibody is 80 μ g/mL. The optimum immobilization time for antibody is 90 min. Directional immobilization of EBV antibody is achieved by high affinity binding of protein A to the Fc segment of antibody. When antigen specifically binds to antibody, the formation of immune complexes blocks electron transfer of [Fe(CN)6] 4-/3- and is reflected in the detection of cyclic voltammetry/electrochemical impedance spectroscopy. The detection range is 1 pg/mL–l00 ng/mL with a LOD of 0.1 pg/mL. In addition, the proposed sensor exhibited an excellent antiinterference property.