title: Electrochemical impedance immunosensor based on three-dimensionally ordered macroporous gold film.
abstract: A novel label-free immunosensor for the detection of C-reactive protein (CRP) was developed based on a three-dimensional ordered macroporous (3DOM) gold film modified electrode by using the electrochemical impedance spectroscopy (EIS) technique. The electrode was electrochemically fabricated with an inverted opal template, making the surface area of the 3DOM gold film up to 14.4 times higher than that of a classical bare flat one, characterized by the cyclic voltammetric (CV) technique. The 3DOM gold film which was composed of interconnected gold nanoparticles not only has a good biocompatible microenvironment but also promotes the increase of conductivity and stability. The CRP immunosensor was developed by covalently conjugating CRP antibodies with 3-mercaptopropionic acid (MPA) on the 3DOM gold film electrode. The CRP concentration was measured through the increase of impedance values in the corresponding specific binding of CRP antigen and CRP antibody. The increased electron-transfer resistance (R(et)) values were proportional to the logarithmic value of CRP concentrations in the range of 0.1 to 20 ng mL(-1). The detection of CRP levels in three sera obtained from hospital showed acceptable accuracy.
authors.affiliation: Key Laboratory of Analytical Chemistry for Life Science, Ministry of Education of China, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, People's Republic of China.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Chen
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Wang
authors.forename: Jinjun
authors.initials: J
authors.lastname: Zhou
authors.forename: Wei
authors.initials: W
authors.lastname: Yan
authors.forename: Xinghua
authors.initials: X
authors.lastname: Li
authors.forename: Jun-Jie
authors.initials: JJ
authors.lastname: Zhu
mesh_terms: D015374:Biosensing Techniques; D002097:C-Reactive Protein / Q000032:analysis; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D006046:Gold; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods*; D053768:Metal Nanoparticles; D008855:Microscopy, Electron, Scanning; D015203:Reproducibility of Results
chemical_list: D006046:Gold; D002097:C-Reactive Protein