Recent Advances in Nucleic Acid-Based Electrochemical Sensors for the Detection of Food Allergens

Food allergies represent a growing public health concern, requiring analytical methods capable of detecting trace levels of allergenic ingredients in increasingly complex and processed food matrices. In recent years, nucleic acid-based electrochemical sensors have emerged as a powerful alternative to protein-targeting assays, offering improved stability and sequence specificity, as well as compatibility with portable, low-cost sensing platforms. This review provides a comprehensive overview of nucleic acid-based sensing strategies developed for detecting either allergen proteins or nucleic acids related to allergenic species. Particular attention is given to the methodological approaches implemented, which for DNA detection include sandwich-type designs and DNA switches, while for protein detection rely on aptamer-based assays in a labelled or label-free setup. The review also discusses the impact of pre-analytical steps, such as nucleic acid extraction and PCR-based amplification, on assay reproducibility, cost and applicability at the point of need. Although significant improvements in analytical performance have been achieved, challenges remain in terms of simplifying workflows, standardizing methods, validating them on a large scale, and developing continuous monitoring schemes for timely intervention. The review highlights emerging opportunities, including multiplexed detection platforms, robust extraction protocols, and the harmonization of allergen thresholds, which are key to supporting the practical implementation of nucleic acid-based sensors.