Bioinspired Spatial Compartment of Substrate Molecules and Catalytic Counting Entities in Hierarchical MOFs Initiated for a Dual-Mode Glycoprotein Assay

Living cell systems possess multiple isolated compartments that can spatially confine complex substances and shield them from each other to allow for feedback reactions. In this work, a bioinspired design of metal–organic frameworks (MOFs) with well-defined multishelled matrices was fabricated as a hierarchical host for multiple guest substances including fluorogenic molecules and catalytic nanoparticles (NPs) at the separated locations for the development of a dual-mode glycoprotein assay. The multispatial-compartmental zeolitic imidazolate framework-8 (ZIF-8) constituents were synthesized via epitaxial shell-by-shell overgrowth to guide the integration and spatial organization of host guests. The specific property toward glycoprotein recognition was guaranteed by both the antibody–antigen recognition and covalent bonding through boronate-glycan affinity, and the immediate signal responses were initiated by textural collapse of the ZIF-8 integrity. In addition, the inner micropore and the enclosed space of ZIF-8 can avoid the surpassed contact between molecular substances and catalytic entities, inherently. Furthermore, multishelled ZIF-8 can function as a hierarchical matrix for hosting abundant fluorogenic substrates and a large number of catalytic Pt-shelled Au (AuPt) NPs, which can signify its signal amplification means, while upon the stimuli-responsive framework collapse, the signal generators can be harvested in the on-demand manner. Besides, endowing Pt shells on inert plasmonic NPs can not only mimic peroxidase-like catalytic behavior involved in a fluorogenic catalytic reaction to generate fluorescence signals but also function as scattering signal reporters, which can also signify the dynamic light scattering output signals. Collectively, our proposed method may provide a new thought in combining the well-defined multishelled MOF matrices for dual-signal generators in a stimuli-responsive manner, which can also reinforce the accurate detection capability for the glycoprotein assay.