Printable Core-Shell Nanoparticles Empower Stable Biosensing
Wearable and implantable biosensors enable real-time monitoring of physiological parameters and biomarkers such as glucose, lactate, and hormones, but face persistent limitations in selectivity, operational lifespan, and scalable manufacturing. Molecularly imprinted polymers (MIPs) and Prussian blue analogues (PBAs) offer customizable recognition and redox activity, yet PBAs degrade over electrochemical cycling and MIPs suffer from imprecise binding-site optimization. Wang et al. (Nat. Mater., 2025, 24, 589–598) address these bottlenecks with printable core-shell nanoparticles comprising a nickel hexacyanoferrate (NiHCF) core and an MIP shell. The NiHCF core, synthesized via a citrate-assisted method, yields uniform nanocubes with low lattice strain due to nickel's small atomic radius, retaining 95% of its redox signal after 5000 electrochemical cycles—significantly outperforming conventional PBAs. Density functional theory (DFT) calculations guided monomer selection to ensure precise molecular complementarity within the MIP cavity, resolving inefficient molecular recognition. Formulated into an inkjet-printable ink, the MIP/NiHCF nanoparticles enable scalable, additive manufacturing of biosensors. This platform establishes a new benchmark for wearable and implantable health monitoring, though challenges remain in extending dynamic range to picomolar cytokines, ensuring long-term stability in complex biofluids, and validating performance across diverse populations. The integration of molecular imprinting, redox-active nanomaterials, and additive manufacturing provides a foundation for next-generation diagnostics and therapeutic interventions.