Coordination-Driven Metal-Phenolic Network Complexes for Programmable Colorimetric Signal Transduction and Defined Nano-Bio Interfaces.

Self-assembled coordination networks provide opportunities to engineer functional nanostructures with programmable physicochemical properties, yet their optical responses and nano-bio interfacial interactions remain poorly understood. Herein, we employ a coordination-driven self-assembly approach to construct metal-phenolic network complexes (MPNCs) with tunable optical properties and defined antibody-binding interfaces. The coordination between metal ions and polyphenol ligands enables programmable electronic structures, allowing systematic regulation of colorimetric responses through metal selection. A library of MPNCs built from representative metal ions and polyphenol ligands reveals structure-property relationships governing optical behavior and color generation across diverse metal-ligand combinations. Molecular dynamics simulations uncover strong single-atom binding and adaptive nano-bio interfaces, rationalizing efficient antibody conjugation and functional adaptability of MPNCs. As a proof of concept, the tunable optical properties of MPNCs enable multiplex signal transduction in lateral flow immunoassays (LFIA) for qualitative and quantitative detection of representative neonicotinoid pesticides, acetamiprid and thiamethoxam. The resulting multiplex LFIA demonstrates distinct multicolor outputs, reliable analytical performance, and applicability in complex food samples, highlighting its potential for robust point-of-care testing. This work provides fundamental insights into coordination-regulated optical responses and nano-bio interactions, establishing MPNCs as a versatile platform for programmable signal transduction and advanced bioanalytical applications.