Food allergies to nuts, eggs, milk and seafood are a growing public-health concern, and today's diagnostics are reactive: skin-prick tests and blood draws that are invasive, slow and can themselves provoke mild reactions. A KAUST team has developed AllergE, a wearable microneedle patch that reads immunoglobulin E, the antibody that triggers allergic reactions, directly from interstitial fluid, aiming to flag sensitisation before a reaction ever occurs.
The porous needles, under a millimetre long and roughly the width of a human hair, are fabricated by two-photon polymerisation, a high-resolution 3D lithography technique that precisely controls their geometry and strength. DNA aptamers inside each needle change shape when they bind IgE, generating an electrochemical signal that a flexible electrode and compact reader translate into data. In tests on artificial skin substitutes and explanted human donor skin, the sensor detected IgE at concentrations as low as 30 picograms per millilitre and distinguished it from structurally similar antibodies.
The project, published in ACS Materials Letters, grew out of a collaboration between Dana Alsulaiman's biomedical materials lab and Khaled Salama's Sensors Lab, and was inspired by former doctoral student Esraa Fakeih's experience of severe food allergy in her own family. The work remains preclinical, but the team envisions a family of painless skin-worn diagnostics, with continuous at-home allergy monitoring synced to a smartphone as the first target.