Streptavidin‐polypyrrole Film as Platform for Biotinylated Redox Probe Immobilization for Electrochemical Immunosensor Application

Abstract

1IntroductionElectrochemical immunosensors have proved to be promising devices in several fields such as clinical [1],p harmaceuticala pplications and environmental control [ 2]. Indeed,t hey had many advantages,s uch as robustness, low cost, high sensitivity and portability.T heir construction and use are very simple and allow detection of as mall scale (low volume, concentration, small surface …). Immunosensors are generally constructed by initially antibodies immobilization on an electrode surface,w hich is then allowed to interact with its specific antigen. As antibody and antigen are intrinsically unable to act as redox partners,d ifferent strategies are used to convertt he immunoreactioni nto electrochemical transduction event [3].T he mostp opular are the use of redox reactionf rom either al abeled secondary antibody by redox markers [4] or enzyme able to provide redox products upon enzymatic reaction such as peroxidases [5].A ddition of redox reagent such as K 4 Fe(CN) 6 /K 3 Fe(CN) 6 in the solutionw as also performed to follow the antigen/antibodies complex formation [6].T his provides ac urrent proportional to the analytec oncentration. However, other electrochemical transduction approaches without labelingb iomolecules were performed, such as using carbon nanotubes [7], nanoparticles [8] and conducting polymers [9,10].Electrochemical immunosensors based on conducting polymer are alreadyp rovided to be interesting analytical devices able to followt he complex antigen/antibody formation in real time.I ndeed, the electronics tructure of polymer layer is sensitive to any modifications of the backbone conjugation and the conformation related to ab iological interaction [11].M oreoverc onductingp olymers exhibit an ability to provide as uitable interface for anchoringa ntibodies onto electrode surface without alteration of their biological activities [12].A mong of conducting polymers used in sensing applications,polypyrrole (Ppy) has been well studied due to its biocompatibility, high hydrophilic charactera nd high stabilityi nw ater. However the polymerl ayers impose diffusion barriers,i n particular for large biomolecules,s uch as proteins,r esult-Abstract:Aplatform for constructiono fm ulti-array electrochemical immunosensors was developed in which the measurementc ould be performed by varioust argets dependingo nt he potential ranges of electrochemicald etection. This was demonstrated by the immobilization of biotinylated redox molecules such as viologena nd ferrocene, on modified polypyrrole-streptavidin film. Thep olypyrrole film was modified by streptavidin layer, which serves for botht he attachment of biotinylatedr edox marker and biotinylated antibody.S uch biologicallym odified surface exhibits variation of electrochemicalr esponse of redox molecule at various potential ranges after antibody/antigen interaction.T he measuremento fr edox signal of viologen and ferrocene was analyzedb yd ifferential pulse voltammetry (DPV) methoda nd underlines avariation of redox properties upon the antigen inter...

Viologen-functionalized single-walled carbon nanotubes as carrier nanotags for electrochemical immunosensing. Application to TGF-β1 cytokine

“…A platform for the construction of multi-array electrochemical immunosensors was prepared by immobilization of biotinylated viologen on modified polypyrrole-streptavidin films. In this strategy, the change in the electrochemical response of the redox molecule corresponding to the two electrons reduction of di-cationic to neutral viologen was monitored after the antibody-antigen interaction [Miodek et al, 2016]. The direct impedimetric detection of an anti-cholera toxin antibody was performed by using electropolymerized biotinylated poly(pyrrole-viologen) film as scaffold for the development of reagentless immunosensors [Gondram et al, 2010].…”

Nanocomposite Based on Poly (para-phenylene)/Chemical Reduced Graphene Oxide as a Platform for Simultaneous Detection of Ascorbic Acid, Dopamine and Uric Acid

“…Conducting polymers (CPs) with π-conjugated backbones have been widely used for enhancing the detection of AA, DA or UA thanks to their remarkable electronic properties [16,17]. Electroactive polymers integrating redox system demonstrate the catalytic effect that enhances the sensitivity toward AA, DA and UA detection [18,19]. Electrode-modified graphene have been also demonstrated for simultaneous detection of AA, DA and UA [20,21].…”

Clinically Relevant Detection ofStreptococcus pneumoniaewith DNA-Antibody Nanostructures

“…Electrochemical sensors can fill that gap due to their advantages of simple operation, low cost, high sensitivity, and efficiency. − The highly specific recognition between antigens and antibodies also confers high selectivity among the diverse microbiome of the upper respiratory tract. Electrochemical immunosensors determine the presence of antigens by detecting the changes in current, capacitance, potential, impedance, or conductance resultant from immunoreactions. − After the primary immobilized antibody (Ab) captures the antigen (Atg), a secondary enzyme-labeled Ab is injected onto the electrode to form a sandwich assay. , The enzymatic reaction between the enzyme and enzymatic substrate results in the production of an electroactive molecule, which transmits an electrochemical signal . Alternatively, nonenzymatic-labeled-antibody combined electroactive tag could generate a large amount of redox markers to achieve electrochemical sensing, as shown in Figure a.…”