Gliadin-coated gold nanoparticles for rapid colorimetric test for celiac disease†
Celiac disease (CD) is an immune-mediated disorder affecting the small intestine in genetically predisposed individuals. Despite the significant progress made in research on CD, there is still an urgent need for accurate detection or a point-of-care test for the rapid diagnosis of the disease. In this paper, we present a novel detection test for CD based on the coating of gold nanoparticles with gliadin, the highly antigenic protein that induces CD. Although the protein is cheap and stable, its hydrophobic nature prevented its efficient use in diagnostics. In our work, we successfully demonstrated the binding of the whole hydrophobic gliadin protein to the surface of the gold nanoparticles that we further translated into a simple assay for the detection of CD specific biomarkers in serum as well as saliva. Finally, we compared the diagnostic accuracy of the novel test on 30 previously tested patient serum samples and saliva from 35 untested participants in a blinded assessment that were further compared to the previous serological and pathological tests on those patients. The data showed that the developed test using gold nanoparticles had an overall accuracy of over 96% in detecting celiac disease. Our developed test method offers a substantial advantage over the existing blood tests by eliminating multiple steps associated with routine serological testing, providing results within 15–30 minutes that can be determined by eye without any specialized equipment for signal reading. Finally, the developed assay is valuable for testing CD patients using saliva as a non-invasive, point of care test.