Au/CeO<sub>2</sub> NR Restricted Inside Cu-MOFs: A Three-in-One Artificial Enzyme with Synergistically Enhanced Peroxidase-Like Activity for Dual-Mode Sensing of Multiple Biomarkers
Panpan Chen, Yan Peng, Lin Lan, Yaoyao Yuan, Jie Chen, Jinling Mo, Jiayi Miao, Hongliang He, Yang Jin, Liying Zhang, Shuhu Du
Abstract
Nanomaterials with inherent enzyme-mimetic properties have been extensively studied in biosensing field, but it is still challenging to overcome their natively weak enzyme-mimetic activity and further promote their stabilities. In this work, a three-in-one artificial enzyme with synergistically enhanced peroxidase-like activity and outstanding stability is constructed by restricting Au-loaded CeO 2 nanorods (NR) (1% Au:CeO 2 mass ratio) inside Cu-based metal–organic frameworks (Cu(PABA)), termed Au 1 /CeO 2 NR@Cu(PABA). It has been demonstrated that the artificial enzyme possesses significantly improved performance in catalytic decomposition of H 2 O 2, with ∼2.41 and ∼1.49 times higher activity than its individual constituents (Au 1 /CeO 2 NR and Cu(PABA)), benefiting from the synergistic effect and the unique restricted structure; owns strong affinities to substrates, with separately ∼8.21- and ∼3.13-fold lower Michaelis constants toward H 2 O 2 and o -phenylenediamine, respectively, than horseradish peroxidase; and exhibits desirable pH (4–12), thermal (30–80 °C), organic solvent ( N, N -dimethylformamide, acetone, methanol, etc.), and long-term storage (30 days) stabilities, advantaging practical applications. Taking aforementioned superior properties of Au 1 /CeO 2 NR@Cu(PABA), a universal colorimetric/fluorometric dual-mode sensing platform is built and utilized for detection of biomarkers (e.g., glucose, galactose, and cholesterol) in biological fluids with satisfactory recoveries (90.2–108%). This work offers new horizons in designing high-efficiency, stable, and credible biomimetic catalysts to accelerate future advanced engineering of nanozymes.