Fabrication and modeling of an ultrasensitive label free impedimetric immunosensor for Aflatoxin B₁based on poly(o-phenylenediamine) modified gold 3D nano electrode ensembles

Abstract

An ultrasensitive label free impedimetric immunosensor for AFB1 detection was fabricated based on Poly(ophenylenediamine) (PoPD) electropolymerized film modified gold three dimensional nanoelectrode ensembles (3DNEEs). The nanoelectrode ensembles were fabricated by template synthesis in track etched polycarbonate (PC) membranes. Scanning electron microscopy and X-ray diffraction were used for the evaluation of the properties of 3DNEEs. Anti-AFB1 was directionally immobilized on Staphylococcus protein A (SpA) with orientation function. Cyclic voltammetry and electrochemical impedance spectroscopy were employed to characterize the fabrication process and optimize working conditions. The interface model of molecular recognition was constructed and reasonably interpreted. The detection limit was 0.019 ng/mL (S/N=3). The linear detection concentration range of AFB1 was from 0.04 to 8.0 ng/mL.

Electrochemical Impedance Spectroscopy (EIS) Based Label-Free Immunosensors

“…85 Polymers such as o-aminobenzoic acid (o-ABA) and o-phenylenediamine (o-PD) have been electrodeposited onto electrodes resulting in the partial insulation of the electrodes while still allowing for impedimetric response and have reducing nonspecific specific absorption onto the electrode surface. [86][87][88][89][90][91][92] o-ABA has a carboxylic acid functional group and o-PD has an amine functional group, through which proteins can be immobilised onto the surface.…”

“…88,207 And furthermore, devices are emerging for food security, looking for contaminants such as pathogenic Escherichia coli, [250][251] Ochratoxin A 252 and Aflatoxin B1. 89,[253][254][255] Samples for real applications in food security generally need to be centrifuged or filtered, which is currently hindering their POC implementation. Testing for contaminants in water or dairy products such as milk or infant formula proves less restrictive.…”

Recent advances in nanomaterials integrated immunosensors for food toxin detection

“…Also, the three-dimensional shape structured of nanoelectrode ensembles has been shown widely interest in the construction of biosensor due to their special configuration and large surface area. Hu et al have developed poly(ophenylenediamine) (PoDD) electropolymerized film modified gold three-dimensional nanoelectrode ensembles, fabricated by template synthesis in track-etched polycarbonate membrane (Hu et al 2015). Label-free PoDD modified AFB 1 impedimetric electrode has shown good performance in immunosensing applications because of large active surface area, conductive nature and presence of conducive amino and imino functional groups.…”

Nanobiosensing with Arrays and Ensembles of Nanoelectrodes

“…Anti prostate-specific antigen (PSA) was electrodeposited with polypyrrole on 3D-gold nanowires to develop a label free immunosensor for PSA antigen [ 117 ]. 3D-gold NEEs modified with molecular imprinted poly(o-phenylenediamine) (PoPD) were exploited for aflatoxin B1 detection, reaching a detection limit of 19 fg·mL −1 by electrochemical impedance spectroscopy [ 118 ]. Molecular imprinted polyphenol was deposited on ensembles of Au-nanowires to develop a sensor for epithelial ovarian cancer antigen-125 [ 119 ].…”