Electrochemical biosensor based on self-assembled monolayers modified with gold nanoparticles for detection of HER-3

•Single frequency impedance technique was firstly used for characterization of interaction between HER-3 and anti-HER-3.•Anti-HER-3 antibody was firstly utilized in an immunosensor as a bioreceptor.•The biosensor exhibits high analytical performance with a linear range 0.2–1.4 pg mL−1.•Kramers–Kronig transform was successfully performed on the experimental impedance data.

We have developed a new immunological biosensor for ultrasensitive quantification of human epidermal growth factor receptor-3(HER-3). In order to construct the biosensor, the gold electrode surface was layered with, hexanedithiol, gold nanoparticles, and cysteamine, respectively. Anti-HER-3 antibody was covalently attached to cysteamine by glutaraldehyde and used as a bioreceptor in a biosensor system for the first time by this study. Surface characterization was obtained by means of electrochemical impedance spectroscopy and voltammetry. The proposed biosensor showed a good analytical performance for the detection of HER-3 ranging from 0.2 to 1.4 pg mL−1. Kramers–Kronig transform was performed on the experimental impedance data. Moreover, in an immunosensor system, the single frequency impedance technique was firstly used for characterization of interaction between HER-3 and anti-HER-3. Finally the presented biosensor was applied to artificial serum samples spiked with HER-3.

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