Celiac disease， characterized by autoimmune reactions to dietary gluten， affects up to 3 million in the US and approximately 0.5%-1% globally. A strict， lifelong gluten-free diet is the only treatment. An economic， simple， accurate， rapid and portable gluten testing device would enable gluten-sensitive individuals to safeguard their food safety. We developed a novel solution， Nima™， a gluten sensor that integrates food processing， gluten detection， result interpretation and data transmission in a portable device， detecting gluten proteins at or below the accepted 20 ppm threshold. We developed specific monoclonal antibodies， an optimized lateral flow immunoassay strip， and one-step aqueous extraction. Compared with reference R5， Nima antibodies (13F6 and 14G11) had 35- and 6.6-fold higher gliadin affinities， respectively. We demonstrated device performance using a comprehensive list of foods， assessing detection sensitivity， reproducibility， and cross-reactivity. Nima™ presented a 99.0% true positive rate， with a 95% confidence interval of 97.8%-100%.