Self-enhanced peroxidase-like activity in a wide pH range enabled by heterostructured Au/MOF nanozymes for multiple ascorbic acid-related bioenzyme analyses
Wendong Liu, Dingding Zhang, Fanghua Zhang, Zhe Hao, Yuyan Li, Mingzheng Shao, Ruizhong Zhang, Xiyan Li, Libing Zhang
Abstract
their porous atomic structures and more active sites. Herein, a gold nanoparticles/metal-organic framework (MOF) heterostructure was prepared using UiO-66 as a stable support structure (Au NPs/UiO-66), which demonstrates enhanced peroxidase-like activity, ∼8.95 times higher than that of pure Au NPs. Strikingly, Au NPs/UiO-66 exhibits excellent stability (maintains above 80% activity at 40-70 °C and retains 93% activity after 3 months of storage) and sustained high relative activity (above 90%) over a pH range of 5.0-9.0 due to the homogeneous dispersibility of free-ligand Au NPs and the strong chemical interaction between the Au NPs and the UiO-66 host. Moreover, a colorimetric assay of ascorbic acid (AA) and three AA-related biological enzymes was developed based on Au NPs/UiO-66 nanozyme, which has a good linear detection range and excellent anti-interference ability. This work provides important guidance for the expansion of metal NPs/MOF heterostructure nanozymes and their application prospects in the development of biosensors.