Amperometric Quantification of Gluten in Food Samples Using an ELISA Competitive Assay and Flow Injection Analysis

Abstract

Abstract Gluten analysis in food is intricate because of the analyte variability among cereal species and protein states. Herein the immunodominant peptide 33‐mer from alpha2‐gliadin is proposed as standard for calibration in a competitive ELISA assay with amperometric flow‐injection detection. Using the monoclonal antibody G12, a correlation between the content of gluten in peptide and gluten units was obtained for the first time. The analytical features were compared with optical measurements using several standards obtaining a slightly lower detection limit, which suggested the sensitivity is limited by affinity and not by the detection technique. “Gluten‐free” samples were satisfactorily analyzed.