Construction of smartphone-assisted electrochemical molecularly imprinted sensor based on magnetic MOF@COF as a novel platform for portable and sensitive detection of staphylococcal enterotoxin B

Staphylococcal enterotoxin B (SEB), a major foodborne toxin and bioterrorism agent, poses significant threats to global public health security. To address the urgent need for rapid on-site detection, we report an electrochemical molecularly imprinted sensor based on magnetic core-shell architecture, where two porous framework materials are covalently integrated as the imprinted matrix. The sensor exhibited high selectivity, showing a wide linear range from 5 × 10 −11 to 5 × 10 −5 g·mL −1 and a low detection limit (LOD) of 1.6 × 10 −12 g·mL −1 . Excellent stability and reproducibility were demonstrated in the analysis of spiked milk and water samples. Furthermore, the proposed imprinted nanomaterial exhibited satisfactory results in milk and water samples. Additionally, a portable smartphone-based sensing platform was constructed by integrating the Fe 3 O 4 @MOF@COF@MIP. This platform enabled the on-site determination of SEB with a LOD of 3.3 × 10 −12 g∙mL −1 . The combination of novel magnetic molecularly imprinted composites with mobile detection technology provides a powerful, field-deployable tool for SEB monitoring, advancing the application of multifunctional nanomaterials in biosensing and biodefense.