Precise detection of IgG molecules using AuNP anchored, PEDOT-MoS 2 based electrochemical sensor

Abstract

We report on gold nanoparticle (AuNP) anchored PEDOT-MoS2 based immunosensor probes for rapid electrochemical detection of the specific antigen. After structural and morphological characterization, the AuNP/PEDOT-MoS2 composite electrodes were subjected to Cyclic voltammetry (CV) and impedance spectroscopy (EIS) studies. The electroactivity and interfacial charge transfer kinetics of the electrodes were exploited in 0.1 M phosphate buffer solution (PBS) containing 5 mM K3[Fe(CN)6] as redox probe. Further, the immunosensor was developed considering cross linking of glutaraldehyde over AuNP/PEDOT-MoS2 electrode. Monitored by electrochemical means, an observable rise in current trend upon detection of specific antigen was believed to be due to suitable interfacial changes of the bioelectrode under study. Differential pulse voltammetry (DPV) technique provided the sensing parameters with the help of the calibration equation. It is observed that the antibody-antigen interaction taking place in our system follows Langmuir adsorption isotherm with the adsorption coefficient value, 27.5 L/g. The limit of detection (LOD) and sensitivity of the as prepared immuno-responsive biosensor was estimated to be 81.46 pM and 1.8456 (µA/(ng/mL) cm2) respectively under a wide linear range of 7.7-263 ng/mL.