Mesoporous Ce-UiO-66 with enhanced laccase-like activity for fast detection of epinephrine and specific identification of tetracycline antibiotics

Abstract

The challenges associated with the practical application of natural laccase, such as poor reusability and intrinsic fragility, have driven the exploration of alternative solutions. In particular, cerium-based nanozymes emerge as promising candidates due to their high O₂ mobility and inherent redox reactivity. However, there is a need for more in-depth and systematic research to enhance their catalytic activity and expand their application areas. Herein, a mesoporous cerium-based MOF material (MPUiO-66(Ce)) was synthesized with the cooperative assembly of amphiphilic molecular template and framework precursors. Compared with natural laccase, MPUiO-66(Ce) exhibited ∼4.3-fold higher catalytic efficiency, along with enhanced stability under harsh conditions. Besides, the catalytic efficiency of MPUiO-66(Ce) was ∼4.0-fold higher than that of non-porous Ce-UiO-66 (NPUiO-66(Ce)). This enhancement can be attributed to its mesoporous structure, which acted as bionic pockets and provided favorable conditions for the effective diffusion and capture of substrates. Based on the above advantages, MPUiO-66(Ce) was employed for colorimetric sensing epinephrine (EP) and tetracycline (TC), respectively. EP can be detected within 5 min, resulting in a low detection limit of 400 nM and a broad linear range of 10–220 μM. Besides, the MPUiO-66(Ce)-based colourimetric platform could discriminate TC from other antibiotics, showing a wide linear range (20–250 mΜ) and a low detection limit of 810 nM. Furthermore, this sensing platform can accurately identify EP in serum, as well as TC in tap water, river water and soil. This work provided a new approach for designing cerium-based nanoenzymes with improved catalytic activity and highlighted their potential applications in the fields of life analysis and environmental monitoring.