title: Development of an amperometric biosensor based on peroxidases to quantify citrinin in rice samples.
abstract: An amperometric biosensor based on horseradish peroxidase (EC1.11.1.7,H2O2-oxide-reductases) to determine the content of citrinin mycotoxin in rice samples is proposed by the first time. The method uses carbon paste electrodes filled up with multi-walled carbon nanotubes embedded in a mineral oil, horseradish peroxidase, and ferrocene as a redox mediator. The biosensor is covered externally with a dialysis membrane, which is fixed to the body side of the electrode with a Teflon laboratory film, and an O-ring. The reproducibility and the repeatability were of 7.0% and 3.0%, respectively, showing a very good biosensor performance. The calibration curve was linear in a concentration range from 1 to 11.6nM. The limits of detection and quantification were 0.25nM and 0.75nM, respectively. For comparison, the citrinin content in rice samples was also determined by fluorimetric measurements. A very good correlation was obtained between the electrochemical and spectrophotometric methods.
authors: Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Agencia Postal No. 3 (5800)-Río Cuarto, Argentina.
authors: Vanesa Gimena Lourdes
authors: VG
authors: Zachetti
authors: Adrian Marcelo
authors: AM
authors: Granero
authors: Sebastián Noel
authors: SN
authors: Robledo
authors: María Alicia
authors: MA
authors: Zon
authors: Héctor
authors: H
authors: Fernández
mesh_terms: D031215:Armoracia / Q000201:enzymology; D015374:Biosensing Techniques / Q000379:methods*; D002953:Citrinin / Q000032:analysis* / Q000378:metabolism; D004800:Enzymes, Immobilized / Q000378:metabolism; D006735:Horseradish Peroxidase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D057230:Limit of Detection; D012275:Oryza / Q000737:chemistry* / Q000382:microbiology; D015203:Reproducibility of Results
chemical_list: D004800:Enzymes, Immobilized; D002953:Citrinin; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase