title: Label-free photoelectrochemical immunosensor for sensitive detection of Ochratoxin A.
abstract: A general label-free photoelectrochemical (PEC) platform was manufactured by assembly of CdSe nanoparticles (NPs) sensitized anatase TiO2-functionalized electrode via layer-by-layer (LBL) strategy. CdSe NPs were assembled on anatase TiO2-functionalized electrode through dentate binding of TiO2 NPs to -COOH groups. Ascorbic acid (AA) was used as an efficient electron donor for scavenging photogenerated holes under visible-light irradiation. The photocurrent response of the CdSe NPs modified electrode was significantly enhanced as a result of the band alignment of CdSe and TiO2 in electrolyte. Ochratoxin A (OTA), as model analyte, was employed to investigate the performance of the PEC platform. Antibodies of OTA were immobilized on CdSe sensitized electrode by using the classic 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride coupling reactions between -COOH groups on the surfaces of CdSe NPs and -NH2 groups of the antibody. Under the optimized conditions, the photocurrent was proportional to OTA concentration range from 10pg/mL to 50ng/mL with detection limit of 2.0pg/mL. The employed PEC platform established a simple, fast and inexpensive strategy for fabrication of label-free biosensor, which might be widely applied in bioanalysis and biosensing in the future.
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Jiaojiao
authors.initials: J
authors.lastname: Yang
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Picheng
authors.initials: P
authors.lastname: Gao
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Yixin
authors.initials: Y
authors.lastname: Liu
authors.affiliation: School of Resources and Environmental Sciences, University of Jinan, Jinan 250022, PR China.
authors.forename: Rongxia
authors.initials: R
authors.lastname: Li
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Hongmin
authors.initials: H
authors.lastname: Ma
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China; School of Resources and Environmental Sciences, University of Jinan, Jinan 250022, PR China. Electronic address: dubin61@gmail.com.
authors.forename: Bin
authors.initials: B
authors.lastname: Du
authors.affiliation: Key Laboratory of Chemical Sensing & Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, PR China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wei
mesh_terms: D015374:Biosensing Techniques / Q000191:economics / Q000295:instrumentation; D019187:Cadmium Compounds / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000191:economics / Q000295:instrumentation*; D004867:Equipment Design; D007118:Immunoassay / Q000191:economics / Q000295:instrumentation*; D008027:Light; D057230:Limit of Detection; D009183:Mycotoxins / Q000032:analysis*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D009793:Ochratoxins / Q000032:analysis*; D015203:Reproducibility of Results; D018036:Selenium Compounds / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*
chemical_list: D019187:Cadmium Compounds; D009183:Mycotoxins; D009793:Ochratoxins; D018036:Selenium Compounds; C009495:titanium dioxide; C025589:ochratoxin A; C058667:cadmium selenide; D014025:Titanium
keywords: CdSe; Label-free; Ochratoxin A; Photoelectrochemical sensor; TiO(2)