A highly sensitive amperometric immunosensor probe based on gold nanoparticle functionalized poly (3, 4-ethylenedioxythiophene) doped with graphene oxide for efficient detection of aflatoxin B1

In the present work, a platform of Poly (3, 4-ethylenedioxythiophene) (PEDOT) and graphene oxide (GO) composite decorated with spherical gold nanoparticles (AuNPs) has been developed for rapid electrochemical detection of aflatoxin B1 (AFB1). Electrochemical deposition of EDOT onto glassy carbon electrode (GCE) keeping GO as dopant followed by introduction of AuNPs has been achieved resulting in nanohybrid AuNPs/PEDOT-GO electrode. The antibody anti-aflatoxin B1 (anti-AFB1) has been further covalently immobilized onto the surface of AuNPs/PEDOT-GO using EDC/NHS coupling. The morphological and surface characteristics have been studied using Field Emission Scanning Microscopy (FESEM) and contact angle measurements. Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) studies have been carried out to investigate the electro-catalytic behavior of the modified electrodes. The heterogeneous rate constant (ks) and transfer coefficient (α) have been determined by using Laviron's method. The proposed immunosensor exhibits a very high sensitivity of 0.989 μA ng mL−1 and 0.397 μA ng mL−1 within two linear range of 0.5-20 ng mL−1 and 20-60 ng mL−1, respectively.