Green-synthesised carbon dots as nanointerfaces in electrochemical immunosensors for Gly m TI soybean allergen...

Food allergies are a growing global health concern, demanding reliable tools for allergen detection to ensure consumers' safety. This work proposes the development of sustainable carbon dots (CDs) as immunosensor bioreceptors for the sensitive quantification of soybean trypsin inhibitor (Gly m TI) in foods. CDs were synthesised via a green hydrothermal method using eucalyptus leaves as a precursor and integrated onto a gold electrode as a platform to enhance electron transfer, surface functionality, and antibody immobilisation. The resulting immunosensor, constructed with CDs-PAMAM-anti-Gly m TI IgG, exhibited good analytical performance, including a wide dynamic range (1 fg mL^-1 to 0.1 ng mL^-1), a limit of detection (LOD) of 1 ag mL^-1 in buffer, and high specificity, as confirmed by adsorption isotherm modelling. Its applicability was further validated in complex non-/processed food matrices (dough/biscuits, and raw ham/cooked ham), where it maintained a robust performance (LOD <0.1 mg kg^-1) regardless of matrix interferences and/or thermal processing effects. At this sensitivity level, the platform meets international food safety requirements, protecting more than 95% of soybean-allergic consumers worldwide. These findings demonstrate the potential of sustainable CDs-based nanointerfaces as eco-friendly, high-performance platforms for food allergen monitoring and future point-of-care diagnostics.