Strategically engineered magnetic FeMICuMOFs for smartphone-assisted colorimetric and electrochemical surveillance of malachite green residues.

Rapid and accurate detection of Malachite Green (MG) residues in aquatic products is crucial for food safety and public health. Here, we strategically developed a multifunctional FeMICuMOF material through a self-supported molecular imprinting strategy and evaluated its application in electrochemical and smartphone-integrated colorimetric detection of MG. This design integrates an Fe3O4 core with a copper-based MOF coating, featuring specific binding sites for MG. It simplifies the operation and reduces complex matrix interference through magnetic separation, while achieving dual-mode signal transduction via electrochemical and catalytic activities. The presence of MG significantly impacts the electrochemical and catalytic activities of FeMICuMOF through specific recognition, enabling accurate quantification based on its concentration. Our method exhibits excellent analytical performance with low detection limits and applicability for complex samples, and its smartphone integration enables point-of-care testing. This smart material and sensing protocol show significant potential for food safety and environmental monitoring.