Interfacial engineering-tailored self-cascading nanozyme for sensitive and rapid detection of different amylases

The precise quantification of amylases activities in complex environments is crucial in actual manufacturing. We synthesized a self-cascading nanozyme (Au@MOF-235) with glucose oxidase (GOx)-mimicking and peroxidase (POD)-mimicking ability. The stable electrostatic interaction guarantees the homogeneous immobilization of Au nanoparticles with a remarkable GOx-simulating property and thorough active site exposure of MOF-235. Moreover, the generated gluconic acid modulates the acidic level and boosts the POD-mimetic behavior of MOF-235. Consequently, we constructed a platform for sensitive determination of four amylases, demonstrating wide linear ranges (α-amylase: 4-400 U/L, β-amylase: 4-500 U/L, γ-amylase: 10-300 U/L, and pullulanase: 10-400 U/L) and low detection limits (α-amylase: 1.74 U/L, β-amylase: 1.85 U/L, γ-amylase: 5.76 U/L, and pullulanase: 3.68 U/L). This study offers a reliable approach for tracking amylases during food manufacturing with advanced self-cascading and self-activating nanozymes.