Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, International Joint Research Center for Intelligent Biosensing Technology and Health, College of Chemistry, Central China Normal University, Wuhan 430079, PR China.
School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan 430205, PR China.
J Hazard Mater. 2022 Jun 15;432:128707. doi: 10.1016/j.jhazmat.2022.128707. Epub 2022 Mar 15.
Cell-free enzymatic catalysis (CFEC) is emerging biotechnology that simulates biological transformations without living cells. However, the high cost of separation and preparation of the enzyme has hindered the practical application of the CFEC. Enzyme immobilization technologies using solid supports to stabilize enzymes have been regarded as an efficient strategy to address this issue. Nevertheless, the activity and stability of the immobilized enzymes are still crucial challenges for working in vitro. Herein, an enzyme immobilization platform is developed by using PtCu hydrogels coated with amorphous metallic-organic frameworks (MOFs) as multifunctional carriers to encapsulate horseradish peroxidase (HRP). Specifically, PtCu hydrogels acting as a "reservoir of metal ions" can interact with the immobilized enzyme and facilitate electron transfer, leading to the boosted enzyme catalytic performances. Furthermore, amorphous MOFs on the surface of PtCu hydrogels serve as an "armor" to protect the internal enzymes from various perturbation environments. The resultant enzyme immobilization platform (PtCu@HRP@ZIF-8) not only shows an approximately 2.4-fold enhanced activity compared with free enzyme but also exhibits improved stability against harsh conditions. The PtCu@HRP@ZIF-8-based biosensor is constructed for sensitive sensing of organophosphorus pesticides (OPs). The proposed biosensor exhibits a favorable linear relationship with the concentration of paraoxon-ethyl from 6 to 800 ng/mL, with a low detection limit of 1.8 ng/mL. This work reveals the promising potential of our proposed enzyme immobilization platform in practical applications.
无细胞酶催化（CFEC）是一种新兴的生物技术，它可以在无需活细胞的情况下模拟生物转化。然而，酶的分离和制备成本高昂，这阻碍了 CFEC 的实际应用。使用固体载体固定化酶的技术已被认为是解决这一问题的有效策略。然而，固定化酶的活性和稳定性仍然是体外工作的关键挑战。在此，我们开发了一种酶固定化平台，该平台使用涂有无定形金属有机骨架（MOFs）的 PtCu 水凝胶作为多功能载体来包封辣根过氧化物酶（HRP）。具体来说，作为“金属离子储备库”的 PtCu 水凝胶可以与固定化酶相互作用并促进电子转移，从而提高酶的催化性能。此外，PtCu 水凝胶表面的无定形 MOFs 可以作为“保护罩”，防止内部酶受到各种扰动环境的影响。所得的酶固定化平台（PtCu@HRP@ZIF-8）不仅显示出比游离酶约高 2.4 倍的活性，而且在恶劣条件下也表现出更好的稳定性。基于 PtCu@HRP@ZIF-8 的生物传感器用于灵敏检测有机磷农药（OPs）。该生物传感器在 6 至 800ng/mL 范围内对乙基对氧磷的浓度表现出良好的线性关系，检测限低至 1.8ng/mL。这项工作揭示了我们提出的酶固定化平台在实际应用中的有前景的潜力。
