BIENs: biomimetic interface encoding on Fe₃O₄@Au nanoplatforms for multiplexed cytokine profiling

Real-time, synchronous profiling of key inflammatory cytokines such as IFN-γ, IL-6 and TNF-α is critical for understanding and managing dysregulated immune responses, including cytokine storms associated with severe infections. However, conventional immunoassays are not readily compatible with the requirements of rapid, multiplexed analysis in point-of-care settings. Herein, we report a multiplexed electrochemical biosensing platform based on biomimetic interfacial encoding using Fe₃O₄@Au nanoplatforms (BIENs). The core sensing element consists of extracellular vesicle-mimetic nanocomposites functionalized with cell membranes overexpressing specific cytokine receptors, enabling native-like molecular recognition. This encoded biomimetic interface affords high-affinity and selective detection of IFN-γ, IL-6 and TNF-α with wide linear ranges (0.1 ~ 1000 pg/mL) and low detection limits (0.043 ~ 0.159 pg/mL). The sensor exhibits excellent selectivity, operational stability, and reproducibility, and maintains high accuracy in serum samples with minimal matrix interference. Beyond analytical performance, this work establishes a receptor-mimetic interfacial encoding strategy for multiplexed biosensing, offering a versatile and scalable paradigm for the development of next-generation intelligent biointerfaces and dynamic immune monitoring systems.