Studies On Electrochemical Immunoassay Methods Based On Two-dimensional Graphene Materials

A review on electrochemiluminescence?ECL?,Fast Scan Voltammetry?FSV?was carried out.Due to the large surface area and good biocompatibility,GO can be labeled by magnetic iron oxide nanoparticles,antibodies,enzymes or DNA.The formed multi-functionalized GO has widely used in the construction of aptsensor.In this work,a new type of detection method?FSV?was developed on the basis of ECL building sensor,to realize high sensitivity detection of low concentration of tumor markers and marine pathogens.1.Electrochemiluminescence aptasensor for the MUC1 protein based on multifunctionalized graphene oxide nanocompositeThe electrochemiluminescence?ECL?aptasensor was prepared for the detection of Mucin 1 based on its specific recognition by aptamer immobilized on multi-functionalized graphene oxide nanocomposite,which was prepared with N-?4-aminobutyl?-N-ethylisoluminol?ABEI?and aptamer chemically bound to the surface of magnetic GO?nanoFe₃O₄@GO?.ABEI and aptamer acted as the electrochemiluminophore and the capture device for Mucin 1 respectively.NanoFe₃O₄@GO brought multi-functionalized graphene oxide nanocomposite attracted on the surface of magnetic glass carbon electrode through magnetism,enabling all the ABEI immobilized electrochemically active due to its good conductivity and thus then facilitating sensitive detection of Mucin 1.In addition,the ECL aptasensor can be prepared through a one-step process.Under optimal conditions,the ECL intensity of the aptasensor decreased proportiona lly to the logarithmic concentrations of Mucin 1 in the range of 0.005–1000 ng/mL.This aptasensor displays good specificity,stability,reproducibility and application.This method has a large potential in that,such a multi-functionalized graphene oxide nanocomposite also may be applied to other ECL-based aptasensors.2.An electrochemical immunosensor based on graphene oxide and fast scan voltammetry for detection of Vibrio parahaemolyticus.An electrochemical immunosensor for rapid detection of marine pathogenic bacterium Vibrio parahaemolyticus?VP?in seafood was developed based on multi-functionalized graphene oxide and fast scan voltammetry,which was prepared with VP antibody?anti-VP?simultaneously immobilized on the surface of magnetic graphene oxide?nanoFe₃O₄@GO?.And aminoferrocene acted as the electrochemical signal to soluble in solution.Under optimal conditions,when the antiVP capture VP,the ECL intensity decreased with increasing logarithmic concentrations of VP in the range of 102–108 CFU/mL.This ECL immunosensor showed high specificity,stability for the detection of VP.Therefore,the developed immunosensor shows great prospect for potential value and practical application.3.An electrochemical sensor for Vibrio parahaemolyticus based on fast scan voltammetryA novel Faradaycage-type electrochemical sensor was developed based on fast scan voltammetry and graphene oxide?GO?,using anti-VP?Ab1?-Au@Fe₃O₄ as capture unit and aminoferrocene?AFC?&anti-VP?Ab2?@GO as detection unit.With this design,the outer Helmholtz plane of the electrochemical sensor could be extended effectively by the preparation gold-coated Fe₃O₄ nanoparticles.Thus,all labelled AFC molecules could give in-situ electrochemical signals.The electrochemical signal was improved by the fast scan voltammetry,resulting in the improving detection sensitivity.