Portable Dual‐Modular Immunosensor Constructed from Bimetallic Metal–Organic Framework Heterostructure Grafted with Enzyme‐Mimicking Label for Rosiglitazone Detection

Abstract Immunosensor with photoelectrochemistry and fluorescence responsibility is widely used in biomedical detection, health monitoring, and food safety inspection. The cumbersome configuration and low integration of the current immunosensors, however, have brought challenges for their practical applications. To address these challenges, a portable and phone‐APP controlled dual‐modular immunosensor based on a bimetallic metal–organic framework (MOF) heterostructured photoelectrode, ZnO/NiZn‐MOF/CdS, grafted with an enzyme‐mimicking Au@CuO/Cu₂O label is constructed to achieve simultaneous photoelectrochemistry and fluorescence signage. In the electrode design, the construction of a bimetallic NiZn metal–organic framework (NiZn‐MOF) into the common ZnO/CdS photoresponsive structure achieves significant and stable photocurrent output under a very low‐power LED light source for not only accelerating the transfer of photogenerated electrons from CdS to ZnO, but also stabilizing the holes of CdS to improve its photocorrosion resistance. After the graft of multifunctional enzyme‐mimicking Au@CuO/Cu₂O label clusters, a portable dual‐modular immunosensor is built for the detection of rosiglitazone, a common antidiabetic drug and strictly restricted food residual, over a range from 10⁻³ to 1 µg L⁻¹. This MOF‐based immunosensor offers insights into highly sensitive dual‐modular responsive material innovations and provides miniaturized biomedical detectors with promising commercialization potentials.