A Glucose Oxidase-Nanozyme Cascade System with Adjustable Interenzyme Spacing for Glucose Analysis

Here, glucose oxidase (GOD) is connected to Fe₃O₄ nanozyme by using epoxy cross-linkers as a spacer arm to construct a GOD-nanozyme artificial enzyme cascade system that is easy to separate magnetically. The dual-enzyme system can regulate the distance between GOD and nanozyme by changing the chain length of the cross-linker. The optimal interenzyme spacing of 2 nm has led to a significant increase in the cascade activity of the dual-enzyme system to 1400 U/mg, which is 2.5 times higher than the cascade activity of the free two enzymes. The GOD-nanozyme cascade system is applied to glucose assay, which has high sensitivity and selectivity for glucose with the lowest detection limit of 0.1 mM. Even in a system where the concentration of interfering substances is 10 times higher than that of glucose, the GOD-nanozyme cascade system can still specifically recognize glucose. The dual-enzyme system is used to establish a visual analysis device for glucose detection. The design of this visual analysis device provides a new strategy for the visual detection of glucose, which is of great significance for promoting the development of bioenzyme-nanozyme cascade systems in bioanalysis.