Engineering Hollow Nanospheres with Hydrophobic@Hydrophilic Amphiphilic Properties for Enhanced Enzymatic Reactions and High-Performance Bioassays

Gaseous reactant-involved heterogeneous catalysis, particularly oxygen-dependent biocatalysis, generally faces inherent challenges related to the low solubility and low diffusion coefficients of oxygen in aqueous solutions. In this study, we report an efficient air-liquid-solid triphase oxidase enzymatic reaction and bioassay system that utilizes hollow hydrophobic@hydrophilic amphiphilic nanospheres as oxygen nanocarriers. The unique hollow porous structure and hydrophobic internal surface facilitate the storage of oxygen for oxidase enzymatic reactions as revealed by single nanoparticle dark-field microscopy. The outer hydrophilic layer facilitates uniform coating of the oxidase and ensures effective contact with the aqueous solution. This configuration creates an interfacial microenvironment that promotes rapid gas and liquid mass transfer, subsequently increasing the reaction rate of glucose oxidase (a model enzyme) catalysis by a factor of 6.6. Consequently, the triphase bioassay demonstrates superior performance in glucose detection, exhibiting a linear range of up to 30 mM, which is 15 times greater than that of the diphase system. Moreover, the triphase system has great potential for the determination of various biomarkers. This study provides a novel solution to the gaseous reactant deficiency issue encountered in heterogeneous catalysis.