title: Graphene oxide-labeled sandwich-type impedimetric immunoassay with sensitive enhancement based on enzymatic 4-chloro-1-naphthol oxidation.
abstract: A new sandwich-type impedimetric immunosensor based on functionalized graphene oxide nanosheets with a high ratio of horseradish peroxidase (HRP) and detection antibody was developed for the detection of carcinoembryonic antigen (CEA) by coupling with enzymatic biocatalytic precipitation of 4-chloro-1-naphthol (4-CN) on the captured antibody-modified glassy carbon electrode. Two molecular tags (with and without the graphene oxide nanosheets) were investigated for the detection of CEA and improved analytical features were acquired with the graphene-based labeling. With the labeling method, the performance and factors influencing the properties of the impedimetric immunosensors were also studied and evaluated. Under the optimal conditions, the dynamic concentration range of the impedimetric immunosensors spanned from 1.0pgmL(-1) to 80ngmL(-1) CEA with a detection limit (LOD) of 0.64pgmL(-1). Intra- and inter-assay coefficients of variation were less than 7.5% and 11%, respectively. Additionally, the methodology was evaluated for CEA analysis of 10 clinical serum samples and 5 diluted serum samples, receiving in a good accordance with the results obtained by the impedimetric immunoassay and the commercialized electrochemiluminescent method.
authors.affiliation: Key Laboratory of Analysis and Detection for Food Safety (Ministry of Education & Fujian Province), Department of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou 350116, PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Hou
authors.forename: Yuling
authors.initials: Y
authors.lastname: Cui
authors.forename: Mingdi
authors.initials: M
authors.lastname: Xu
authors.forename: Zhuangqiang
authors.initials: Z
authors.lastname: Gao
authors.forename: Jianxin
authors.initials: J
authors.lastname: Huang
authors.forename: Dianping
authors.initials: D
authors.lastname: Tang
mesh_terms: D015374:Biosensing Techniques; D017097:Electric Impedance; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D007118:Immunoassay / Q000379:methods; D049329:Nanostructures / Q000737:chemistry; D009284:Naphthols / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D044967:Serum / Q000737:chemistry
chemical_list: D009284:Naphthols; D010087:Oxides; C025917:4-chloro-1-naphthol; D006108:Graphite