Electrochemical sandwich immunosensor based on porous copper porphyrin hydrogen bond organic framework for accurate quantification of peanut allergen Ara h 1

• A novel sandwich immunosensor was constructed using porous Cu - HOF for Ara h 1 detection. • Cu-HOF has excellent electrocatalytic and conductive properties. • This sensor provides low detection limit (1.92 ng/mL) and wide linear range (80∼8000 ng/mL). • Method was used to test actual samples and standard addition experiments with good accuracy. Peanut allergy is a well-known and potentially life-threatening condition, driving the search for reliable methods for peanut allergens detection. In this study, a novel sandwich-type electrochemical immunosensor was developed using a copper-porphyrin hydrogen-bonded organic framework (Cu-HOF) with outstanding electrochemical performance, enabling highly accurate and sensitive detection of the major peanut allergen Ara h 1. Cu-HOF was utilized as an efficient electrocatalyst toward acetaminophen oxidation to generate a significantly enhanced electrochemical signal. The antibody-modified Cu-HOF forms an immune sandwich structure with the Ara h 1 aptamer electrode in the presence of Ara h 1, triggering the Ara h 1-specific electrochemical detection. The biosensor delivered a broad linear detection range (80∼8000 ng/mL) and a low detection limit of 1.92 ng/mL for Ara h 1. The electrochemical method that was developed was also validated using actual samples and exhibited good consistency with the results from a commercial ELISA kit. This suggests that the developed Ara h 1 biosensor is a valuable tool for the peanut allergy prevention.