Giant magnetoresistive sensor array for sensitive and specific multiplexed food allergen detection

Biosens Bioelectron. 2016 Jun 15;80:359-365. doi: 10.1016/j.bios.2016.02.002. Epub 2016 Feb 2.


Current common allergen detection methods, including enzyme-linked immunosorbent assays (ELISAs) and dip-stick methods, do not provide adequate levels of sensitivity and specificity for at-risk allergic patients. A method for performing highly sensitive and specific detection of multiple food allergens is thus imperative as food allergies are becoming increasingly recognized as a major healthcare concern, affecting an estimated 4% of the total population. We demonstrate first instance of sensitive and specific multiplexed detection of major peanut allergens Ara h 1 and Ara h 2, and wheat allergen Gliadin using giant magnetoresistive (GMR) sensor arrays. Commercialized ELISA kits for Ara h 1 and Ara h 2 report limits of detection (LODs) at 31.5 ng/mL and 0.2 ng/mL, respectively. In addition, the 96-well-based ELISA developed in-house for Gliadin was found to have a LOD of 40 ng/mL. Our multiplexed GMR-based assay demonstrates the ability to perform all three assays on the same chip specifically and with sensitivities at LODs about an order of magnitude lower than those of 96-well-based ELISAs. LODs of GMR-based assays developed for Ara h 1, Ara h 2, and Gliadin were 7.0 ng/mL, 0.2 ng/mL, and 1.5 ng/mL, respectively, with little to no cross-reactivity. These LODs are clinically important as some patients could react strongly against such low allergen levels. Given the limitations of current industrial detection technology, multiplexed GMR-based assays provide a method for highly sensitive and specific simultaneous detection of any combination of food-product allergens, thus protecting allergic patients from life-threatening events, including anaphylaxis, by unintentional consumption.

Keywords: Food allergens; Giant magnetoresistance; Magnetic-based immunoassays; Multiplexed immunoassays; Sensor arrays.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • 2S Albumins, Plant / analysis*
  • Antigens, Plant / analysis*
  • Arachis / chemistry*
  • Biosensing Techniques / instrumentation*
  • Equipment Design
  • Gliadin / analysis*
  • Glycoproteins / analysis*
  • Humans
  • Limit of Detection
  • Magnetics / instrumentation
  • Membrane Proteins
  • Plant Proteins / analysis*
  • Triticum / chemistry*


  • 2S Albumins, Plant
  • Antigens, Plant
  • Ara h 1 protein, Arachis hypogaea
  • Ara h 2 allergen, Arachis hypogaea
  • Glycoproteins
  • Membrane Proteins
  • Plant Proteins
  • Gliadin