▎ 摘　　要

NOVELTY - Probe composition comprises a probe comprising an allergen- or toxin-binding molecule conjugated to a fluorophore, and graphene oxide. The probe adheres to graphene oxide such that the fluorophore is quenched through fluorescence energy resonance transfer (FRET) and the probe dissociates from graphene oxide when bound to a target allergen or toxin. USE - The probe composition is useful for preparing biosensor for detecting and/or quantifying concentration of target allergen or toxin in sample (all claimed). ADVANTAGE - Simple, sensitive and commercially feasible sensors are provided for detecting allergens and toxins. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) a biosensor comprising the probe compositions and a microfluidic device; and (2) a method for detecting and/or quantifying a concentration of a target allergen or toxin in a sample, comprising contacting the sample with the probe composition; and detecting a level of fluorescence of the probe composition in contact with the sample, where the level of fluorescence is proportional to the concentration of target allergen or toxin in the sample.