Rapid diagnosis of egg allergy by targeting ovalbium specific IgE and IgG4 in serum at a disposable electrochemical immunoplatform

Abstract

This work presents an inmunoplatform design for the single and simultaneous determination of two immunoglobulin (Ig) subtypes, specifically IgE and IgG4, considered as reliable markers for the diagnosis and attenuation of food allergy specific to ovalbumin (OVA) (Fig. 1: Schematics for electrochemical immunoassay of the OVA-specific IgE and IgG4). The assay is based on the use of OVA-modified magnetic microbeads bioconjugates for the specific capture of Igs (IgE and IgG4) from serum, which are discriminated in a further step using the specific antibody to the Ig isotype to be detected conjugated with horseradish enzyme. Single or dual amperometric transduction was carried out on (dual) screen-printed carbon electrodes, in the presence of H2O2/hydroquinone system. This approach provides good results in terms of sensitivity (LOD values of 0.003 kU L-1 and 0.0002 μg L-1 for IgE and IgG4, respectively), simplicity and assay time. Both Igs were determined in serum of patients diagnosed with egg allergy with excellent results.