Antibody-Oriented Immobilization for Newcastle Disease Virus Detection Using Label Free Electrochemical Immunosensor Publisher



Norouzi P^{1, 2} ; Nezamoddini M¹ ; Safarnejad MR³ Show Affiliations
Source: Chemical Papers Published:2021

Abstract

In this work, a new label free electrochemical immunosensor was designed to detect Newcastle disease virus (NDV). The immunosensor was constructed by modification of a glassy carbon electrode surface with multi wall carbon nanotubes, gold nanoparticles (AuNPs), 11-Mercapto Undecanoic acid (MUA) and 3-Mercapto Propionic acid. Then, it was stabilized by self-assembly and protein G (PrG) immobilized using 1-ethyl3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-Hydroxy Succinimide to oriented fixation of the antibody. The quantitative measurement of NDV was evaluated by square wave voltammetry method. The determination step was based on the formation of immunocomplex between the antigen and oriented antibody, which caused current decreased in [Fe(CN)6]/K4[Fe(CN)6] redox reaction. The response value was directly proportional to the concentrations of NDV. Scanning electron microscope, XRD, UV and FTIR methods were used to characterize the electrode surface. Also, the electrochemical electrode surface behavior at each step of modification was evaluated by cyclic voltammetry and electrochemical impedance spectroscopy methods. The parameters affecting the performance of the immunosensor such as amount of MWCNT, electrodeposition time of AuNPs, concentration and loading time of PrG, the antibody concentration and antigen incubation time were optimized. The biosensor showed detection limit of 1.6 EID50ml−1 and linear range of 10 to 105 EID50ml−1. The proposed immunosensor showed adequate reproducibility (RSD 6%) and stability (up to one month), which showed that it could be used as a sensitive device for agriculture applications. © 2021, Institute of Chemistry, Slovak Academy of Sciences.