Research On Electrochemical Sensor For Detection Of Hepatitis B Surface Antigen

Hepatitis B virus(HBV)is a potentially disease in human,which have been discussed widely,also gradual become a major problem endangering human health,with the development of modern society.It is conducive to accurate detection of HBV of the treatment and prevention of the disease.Biosensors,a promising method,fast and sensitive analysis of biomolecules,is composed of a bio-logical layer which can interact with the substance to be examinedand a transducer system which can recognize the interaction and transform the biological signal into electrical signal.In this paper,two kinds of electrochemical immunosensors were designed,and HBsAg was used as the target detection object.The main research contents as follows:(1)Preparation of an amperometric immunosensor based on Chitosan-FerroceneAminated multi-walled carbon nanotube/Gold nanoparticles(CS-Fc-AMWNTs/Au NPs)nanocomposites.Firstly,CS-Fc-AMWNTs composite nanomaterials were synthesized by Schiff base reaction.Depending on its’ large specific surface area and good electrical conductivity as an effective sensing platform to immobilized Hepatitis B surface antibody(HBsAb)and accelerated electron transfer.As the redox probe,Fc provides electrochemical signal for immunodetection.HBsAg is captured by specific immune response to form antibody-antigen immune complex,which makes the surface impedance of the electrode increase,and hinders the electronic transmission of Fc,leading the decrease of current signal.The response current is linearly related to the concentration of HBsAg.Finally,the detection of HBsAg can be realized by measuring the magnitude of the generated current.Under optimized conditions,consequently,the working range of HBsAg was 1-250 ng/mL,and the limit of detection was 0.26 ng/mL(S/N=3).It can be concluded that the proposed method may provide promising potential application in clinical immunoassays with the properties of facile procedure,stability,high sensitivity,and selectivity in the detection of HBsAg.(2)An electrochemical immunosensor based on Nanoflower-Gold nanoparticles /Aminated multi-walled carbon nanotubes-Thionine(NF-AuNPs/AMWNTs-THI)composite material farbrication.The AMWNTs-THI composite material were synthesized and coated on the surface of the electrode,and NF-Au NPs composite was prepared by AuS stacking interaction.NF-Au NPs/AMWNTs-THI,due its good conductivity,constituting a sensing interface for adsorbing antibodies and enhancing electron transfer rate.As an electrochemical active probe,copper ion will enhance the electrical signal synergistically with other composite materials.HBsAg was adsorbed by the coated antibody immobilized on the electrode.With the increase of immune complexes,the response current decreases in evidence,and the effect of quantitative detection can be achieved by constructing a relationship between response current and different concentrations of HBsAg.The experimental results showed that the detection range of HBsAg was 0.5-400 ng/mL,and the detection limit was 0.12 ng/mL.The HBsAg immunosensor has exhibited excellent performance with highsensitivity,specificity andrepeatability.The proposed method provides a universal strategy to detect HBsAg.