A cascade nanoreactor based on metal azolate framework integrated natural enzyme for α-glucosidase activity assay and...

Enzyme cascades have attracted widespread attention owing to the exceptional specificity and efficient signals transduction, however, constrained by the high cost and limited stability of bio-enzymes. In this study, a novel mimic multienzyme nanoreactor (GOx@MAF-7(Fe), i.e. GMF) was developed through a one-step encapsulation of glucose oxidase (GOx) into a metal azolate framework, MAF-7(Fe). Benefiting from the synergistic effect of GOx and the exceptional peroxidase-like (POD) activity of MAF-7(Fe), GMF enabled a robust cascade catalytic reaction for colorimetric sensing. The unique structural and functional properties of MAF-7(Fe) not only facilitated efficient enzyme immobilization but also enhanced the stability of GOx, outperforming free enzymes in terms of storage and thermal tolerance. The GMF-based platform demonstrated high sensitivity and selectivity in glucose response. More importantly, by integrating α-glucosidase (α-Glu) into a three-enzyme cascade system, a colorimetric assay was successfully developed for α-Glu activity with a detection limit of 0.25 mU/mL, surpassing most existing methods. This platform was further applied for α-Glu inhibitor screening, with acarbose as a model inhibitor, and achieved precise quantification of inhibition efficiency (IC₅₀ = 60.06 nM). This work not only establishes a versatile and efficient sensing platform for diabetes-related biomolecule detection but also pioneers a novel strategy for enzyme immobilization and multienzyme cascade construction, opening new avenues for multifunctional material design in biomedical research.