Electrochemical immunosensor for the milk allergen β-lactoglobulin based on electrografting of organic film on graphene modified screen-printed carbon electrodes.

摘要: Abstract A novel label-free voltammetric immunosensor for sensitive detection of β-lactoglobulin using graphene modified screen printed electrodes has been developed. The derivatization the electrode surface was achieved by electrochemical reduction in situ generated 4-nitrophenyl diazonium cations aqueous acidic solution, followed terminal nitro groups to amines. modification protocol optimized order generate monolayer nitrophenyl on without complete passivation electrode. Unlike reported method functionalization, we demonstrated here ability electrografting aryl salt attach an organic film a controlled manner choosing suitable grafting protocol. Next, amine were activated glutaraldehyde and used covalent immobilization antibodies. Cyclic differential pulse voltammetry carried out solution containing [Fe(CN)6]3−/4− redox pair have characterization. results that DPV peak current decreased linearly with increasing concentration due formation antibody–antigen complex surface. obtained this approach enabled limit 0.85 pg mL−1 dynamic range from 1 pg mL−1 100 ng mL−1 PBS buffer. In addition, evaluated different samples including cake, cheese snacks, sweet biscuit, showing excellent correlation commercially enzyme-linked immunosorbent assay (ELISA) method.