Accelerating Biocatalysis in Interface-Regulated Nano-Bio Hybrid System via Increasing Substrate Accessibility

Whole-cell biocatalysis of hydrophobic substrates is fundamentally constrained by low solubility and mass transfer limitations, which hinder effective coupling between substrate transport and intracellular metabolism. Herein, we report an interface-regulated nano-bio hybrid system that overcomes these limitations by enhancing substrate accessibility at the microorganism interface. By immobilizing Pseudomonas aeruginosa (Pas) onto a coordination-engineered dicopper material (DTD-Cu), a confined nano-bio interface (Pas@DTD-Cu) is constructed, enabling localized enrichment of hydrophobic substrates and shortening diffusion distances. As a result, the catalysis efficiency of Pas@DTD-Cu is increased to over 200% of that of free bacteria, while maintaining stable activity across a broad pH range (1-11). The increments in ATP, total protein, NADH, and the NAD+/NADH ratio illustrate that the metabolic flux in Pas increases without altering the degradation pathways, suggesting that the performance improvement originates from interfacial regulation rather than pathway modification. This work establishes an interface-controlled strategy for efficient biocatalysis of hydrophobic substrates.