Development of a Graphite Pencil Electrode for Detection of Aflatoxin M1 in Camel Milk Using Differential Pulse Voltammetry

Aflatoxins are important mycotoxins produced by some fungus spp and are resistant to heat treatments such as pasteurization; their concentration remains unchanged, causing threats for humans. In the present study, using differential pulse voltammetry, a pencil graphite electrode based on reduced graphene oxide and gold nanoparticles has been developed to identify aflatoxin in raw camel milk. The behavior of functional electrodes in several processes has been analyzed using cyclic voltammetry and electrochemical impedance spectroscopy. Results showed that stabilization of reduced graphene oxide and gold nanoparticles caused a reduction in current peak and increment in impedance, while by aptamer stabilization and analyte, the current peak has been lowered and impedance increased. According to the differential pulse voltammetry technic, in the 5-800 ng/lit range, electrical current indicated a linear decrease by increasing concentration (R2 =0.991). Recovery was 90-94.5% for a produced biosensor in camel milk. The obtained quantitative detection limit was 3ng/lit. Investigation of functional characteristics, including reproducibility and repeatability, expressed acceptable results for a biosensor.