%0 Journal Article
%A Sánchez Tirado, Esther
%A González Cortés, Araceli
%A Yáñez-Sedeño Orive, Paloma
%A Pingarrón Carrazón, José Manuel
%T Electrochemical immunosensor for the determination of the cytokine interferon gamma (IFN-γ) in saliva
%D 2020
%@ 0039-9140
%U https://hdl.handle.net/20.500.14352/112703
%X A simple, fast and sensitive amperometric immunosensing method for the determination of the clinically relevant cytokine interferon gamma (IFN-γ) in saliva complying the requirements demanded for this kind of sample is reported. The target analyte was sandwiched between a specific capture antibody covalently immobilized on a screen-printed electrode functionalized by the diazonium salt grafting of p-aminobenzoic acid, and a biotinylated detector antibody labeled with a streptavidin-horseradish peroxidase conjugate. The amperometric responses measured at - 0.20 V vs Ag pseudo-reference electrode upon addition of hydrogen peroxide in the presence of hydroquinone as the redox mediator allowed a calibration plot with a linear range between 2.5 and 2000 pg mL−1 and a low limit of detection (1.6 pg mL−1) to be obtained. In addition, a good selectivity against other non-target proteins was achieved. The developed method was validated by analyzing a WHO 1st International Standard for IFN-γ. In addition, the immunosensor was used for the determination of the endogenous IFN-γ in saliva with results in excellent agreement with those obtained by a commercial ELISA kit.
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