title: Development of an impedimetric aptasensor for the determination of aflatoxin M1 in milk.
abstract: An aptasensor was designed for the determination of aflatoxin M1 (AFM1) in milk based on DNA-aptamer recognition and electrochemical impedance spectroscopy detection. A hexaethyleneglycol-modified 21-mer oligonucleotide was immobilized on a carbon screen-printed electrode through carbodiimide immobilization, after diazonium activation of the sensing surface. Cyclic voltammetry and electrochemical impedance spectroscopy in the presence of ferri/ferrocyanide redox probe were used to characterize each step of the aptasensor development. Aptamer-AFM1 interaction induced an increase in electron-transfer resistance, allowing the determination of AFM1 in buffer in the range 2-150 ng/L (LOD=1.15 ng/L). Application to milk analysis showed that a preliminary treatment was mandatory. A simple filtration through a 0.2 µm PTFE membrane allowed determination of AFM1 in milk for concentrations ranging from 20 to 1000 ng/kg. These performances are compatible with the AFM1 levels set in European Union for milk and dairy products for adults (50 ng/kg) and infants (25 ng/kg).
authors.affiliation: Laboratoire BAE, Université de Perpignan Via Domitia, 52 Avenue Paul Alduy, 66860 Perpignan cedex 9, France.
authors.forename: Georges
authors.initials: G
authors.lastname: Istamboulié
authors.affiliation: Laboratoire BAE, Université de Perpignan Via Domitia, 52 Avenue Paul Alduy, 66860 Perpignan cedex 9, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Paniel
authors.affiliation: Laboratoire BAE, Université de Perpignan Via Domitia, 52 Avenue Paul Alduy, 66860 Perpignan cedex 9, France.
authors.forename: Lorena
authors.initials: L
authors.lastname: Zara
authors.affiliation: COVAP, Departamento de I+D+i, Ctra. Canaleja Km 1.5, 1440 Pozoblanco, Córdoba, Spain.
authors.forename: Lucia
authors.initials: L
authors.lastname: Reguillo Granados
authors.affiliation: Laboratoire BAE, Université de Perpignan Via Domitia, 52 Avenue Paul Alduy, 66860 Perpignan cedex 9, France.
authors.forename: Lise
authors.initials: L
authors.lastname: Barthelmebs
authors.affiliation: Laboratoire BAE, Université de Perpignan Via Domitia, 52 Avenue Paul Alduy, 66860 Perpignan cedex 9, France. Electronic address: noguer@univ-perp.fr.
authors.forename: Thierry
authors.initials: T
authors.lastname: Noguer
mesh_terms: D016607:Aflatoxin M1 / Q000032:analysis*; D000818:Animals; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D017097:Electric Impedance; D004563:Electrochemistry; D005026:Ethylene Glycols / Q000737:chemistry; D005506:Food Contamination / Q000032:analysis*; D008892:Milk / Q000737:chemistry*
chemical_list: D052157:Aptamers, Nucleotide; D005026:Ethylene Glycols; C077067:hexaethylene glycol; D016607:Aflatoxin M1
keywords: Aflatoxin M1; Aptamer; Electrochemical impedance spectroscopy; Milk