Development of an impedimetric aptasensor for the determination of aflatoxin M1 in milk

Georges Istamboulié (1) , Nathalie Paniel (1) , Lorena Zara (1) , Lucia Reguillo Granados (2) , Lise Barthelmebs (1) , Thierry Noguer (1)

1 BAE - Biocapteurs-Analyses-Environnement
2 COVAP

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).

Mots clés: Aflatoxin M1; Milk; Aptamer; Electrochemical impedance spectroscopy

Domaines: Chimie

Georges Istamboulié, Nathalie Paniel, Lorena Zara, Lucia Reguillo Granados, Lise Barthelmebs, et al.. Development of an impedimetric aptasensor for the determination of aflatoxin M1 in milk. Talanta, 2016, 146, ⟨10.1016/j.talanta.2015.09.012⟩. ⟨hal-01220620⟩