Disposable electrochemical microfluidic device for ultrasensitive detection of egg allergen in wine samples

Food allergies have been increasing all over the world. Egg is an important component in the food industries and the second most common cause of food allergy, shortly after milk. In the wine industry, egg white is applied as a fining agent for tannin removal. In this study, a sandwich-based immunoassay for ultrasensitive detection of ovalbumin (OVA) in wine samples was developed. The assay involves the use of magnetic beads (MBs) decorated with a polyclonal anti-OVA antibody (Ab2) and horseradish peroxidase (HRP), used as label for the quantification in a disposable electrochemical microfluidic device (DEμD) here developed. The Ab2-MB-HRP prepared was applied to capture, separate, and pre-concentrate OVA from wine samples. In the DEμD, OVA was immune-magnetically captured (OVA-Ab2-MB-HRP), producing a sandwich structure (GO-Ab1-OVA-Ab2-MB-HRP) on the electrode's surface. This arrangement results in an ultrasensitive device, achieving the ultralow limit of detection of 0.2 fg mL−1 OVA. Five samples of wines were analyzed by using the immuno-magneto-assay which presents excellent accuracy compared with enzyme-linked immunosorbent assay (ELISA). [Display omitted] •Ultrasensitive detection of the ovalbumin (OVA) using a disposable electrochemical microfluidic device.•Fast detection of ovalbumin with high sensitivity, selectivity, and low-cost.•Immunosensors based in magnetic beads massively decorated with HRP and Ab2.•A promising analytic device for multiplex detection of other allergens in food.