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Label-Free Detection of Gliadin in Food by Quartz Crystal Microbalance-Based Immunosensor

Funari, Riccardo, Terracciano, Irma, Della Ventura, Bartolomeo, Ricci, Sara, Cardi, Teodoro, D’Agostino, Nunzio, Velotta, Raffaele
Journal of agricultural and food chemistry 2017 v.65 no.6 pp. 1281-1289
antibodies, barley, breads, celiac disease, detection limit, gliadin, gluten, glutenins, gold, hybrids, immunosensors, oats, pasta, pastries, photonics, quartz, rye, texture, wheat
Gluten is a protein composite found in wheat and related grains including barley, rye, oat, and all their species and hybrids. Gluten matrix is a biomolecular network of gliadins and glutenins that contribute to the texture of pastries, breads, and pasta. Gliadins are mainly responsible for celiac disease, one of the most widespread food-related pathologies in Western world. In view of the importance of gliadin proteins, by combining the quartz crystal microbalance technology, a cheap and robust piezoelectric transducer, with the so-called photonic immobilization technique, an effective surface functionalization method that provides spatially oriented antibodies on gold substrates, we realized a sensitive and reliable biosensor for quantifying these analytes extracted from real samples in a very short time. The resulting immunosensor has a limit of detection of about 4 ppm and, more remarkably, shows excellent sensitivity in the range 7.5–15 ppm. This feature makes our device reliable and effective for practical applications since it is able to keep low the influence of false positives.