title: Amplified impedimetric immunosensor based on instant catalyst for sensitive determination of ochratoxin A.
abstract: A new impedimetric immunosensor for the fast determination of ochratoxin A (OTA) in food samples was developed based on the instant catalyst as enhancer. Initially, the signal tags were prepared via co-immobilization of anti-OTA antibody and amine-terminated dendrimer (PAMAM) on the graphene oxide nanosheets through the covalent interaction, which were utilized as a good platform for combining manganese ion (anti-OTA-GO-PAMAM-Mn(2+)). Upon target OTA introduction, a competitive-type immunoreaction was implemented between the analyte and the immobilized OTA-BSA on the electrode for the anti-OTA antibody on the graphene oxide nanosheets labels. After a competitive immunoassay format, the anti-OTA-GO-PAMAM-Mn(2+) were captured onto the electrode surface, which could induce the in situ formation of MnO2via classical redox reaction between Mn(2+) and KMnO4 on the immunesensing platform. Moreover, the generated MnO2 nanoparticles act as efficient catalyst could catalyze the 4-chloro-1-naphthol (4-CN) oxidation without H2O2 to generate an insoluble precipitation on the platform. Under the optimal conditions, the instant catalyst based impedimetric immunosensor displayed a wide dynamic working range between 0.1pgmL(-1) and 30ngmL(-1). The detection limit (LOD) of the assay was 0.055pgmL(-1). The developed method exhibited high selectivity and can be used for the determination of OTA in real red wine samples.
authors.affiliation: Ministry of Education Key Laboratory of Functional Small Organic Molecule, Department of Chemistry and chemical engineering, Jiangxi Normal University, Nanchang 330022, People's Republic of China. Electronic address: juantang@jxnu.edu.cn.
authors.forename: Juan
authors.initials: J
authors.lastname: Tang
authors.affiliation: Ministry of Education Key Laboratory of Functional Small Organic Molecule, Department of Chemistry and chemical engineering, Jiangxi Normal University, Nanchang 330022, People's Republic of China.
authors.forename: Yapei
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Ministry of Education Key Laboratory of Functional Small Organic Molecule, Department of Chemistry and chemical engineering, Jiangxi Normal University, Nanchang 330022, People's Republic of China.
authors.forename: Cengceng
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Ministry of Education Key Laboratory of Functional Small Organic Molecule, Department of Chemistry and chemical engineering, Jiangxi Normal University, Nanchang 330022, People's Republic of China.
authors.forename: Huiqiong
authors.initials: H
authors.lastname: Liu
authors.affiliation: Key Laboratory of Analysis and Detection for Food Safety (Ministry of Education of China and Fujian Province), Department of Chemistry, Fuzhou University, Fuzhou 350108, People's Republic of China. Electronic address: dianping.tang@fzu.edu.cn.
authors.forename: Dianping
authors.initials: D
authors.lastname: Tang
mesh_terms: D000911:Antibodies, Monoclonal / Q000737:chemistry; D002384:Catalysis; D050091:Dendrimers / Q000737:chemistry; D058266:Dielectric Spectroscopy / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005504:Food Analysis / Q000295:instrumentation*; D005506:Food Contamination / Q000032:analysis*; D007118:Immunoassay / Q000295:instrumentation*; D008345:Manganese / Q000737:chemistry*; D009183:Mycotoxins / Q000032:analysis / Q000737:chemistry; D009793:Ochratoxins / Q000032:analysis* / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D000911:Antibodies, Monoclonal; D050091:Dendrimers; D009183:Mycotoxins; D009793:Ochratoxins; C104700:PAMAM Starburst; C025589:ochratoxin A; D008345:Manganese
keywords: Food safety; Impedimetric immunosensor; Instant catalyst; MnO(2) nanoparticles; Ochratoxin A