title: A label-free amperometric immunosensor based on biocompatible conductive redox chitosan-ferrocene/gold nanoparticles matrix.
abstract: A novel experimental methodology based on the unique characteristics of chitosan-branched ferrocene (CS-Fc) and gold nanoparticles (Au NPs) was developed to design a label-free amperometric immunosensor for the sensitive detection of hepatitis B surface antigen (HBsAg) as a model protein. The controllable electrodeposition of CS-Fc solution formed a three-dimensional robust film with good biocompatibility and large surface area for the assembly of Au NPs and further immobilization of hepatitis B surface antibody (HBsAb) on an electrode. The morphologies and electrochemistry of the formed nanocomposite biofilm were investigated by using scanning electron microscopy and electrochemical techniques including cyclic voltammetry and electrochemical impedance spectroscopy, respectively. The HBsAg concentration was measured through the decrease of amperometric responses in the corresponding specific binding of antigen and antibody. The decreased differential pulse voltametric values were proportional to the HBsAg concentration in the range of 0.05-305ngmL(-1) with a detection limit 0.016ng. This would provide an approach for the application of mediator in immunoassays.
authors.affiliation: Department of Chemistry, Nanchang University, Nanchang 330031, People's Republic of China. jdqiu@ncu.edu.cn
authors.forename: Jian-Ding
authors.initials: JD
authors.lastname: Qiu
authors.forename: Ru-Ping
authors.initials: RP
authors.lastname: Liang
authors.forename: Rui
authors.initials: R
authors.lastname: Wang
authors.forename: Li-Xia
authors.initials: LX
authors.lastname: Fan
authors.forename: Yi-Wang
authors.initials: YW
authors.lastname: Chen
authors.forename: Xing-Hua
authors.initials: XH
authors.lastname: Xia
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D017076:Computer-Aided Design; D004553:Electric Conductivity; D004563:Electrochemistry / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005296:Ferrous Compounds / Q000737:chemistry*; D006046:Gold / Q000737:chemistry*; D006514:Hepatitis B Surface Antigens / Q000032:analysis*; D007118:Immunoassay / Q000295:instrumentation*; D000075163:Metallocenes; D053758:Nanoparticles / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013194:Staining and Labeling
chemical_list: D001672:Biocompatible Materials; D005296:Ferrous Compounds; D006514:Hepatitis B Surface Antigens; D000075163:Metallocenes; D006046:Gold; D048271:Chitosan; C004998:ferrocene