Enhancing Enzyme Immobilization on Carbon Nanotubes via Metal–Organic Frameworks for Large-Substrate Biocatalysis

• DOI: 10.1021/acsami.9b01077
• Publication Date: 2019-03-06T15:48:27Z
• Authors: Sunanda Neupane; Kristen Patnode; Hui Li; Kwaku Baryeh; Guodong Liu; Jinlian Hu; Bingcan Chen; Yanxiong Pan; Zhongyu Yang
• Keywords: Biocatalysis; Zeolitic imidazolate framework

Biocatalysis of large-sized substrates finds wide applications. Immobilizing the involved enzymes on solid supports improves biocatalysis yet faces challenges such as enzyme structural perturbation, leaching, and low cost-efficiencies, depending immobilization strategies/matrices. Carbon nanotubes (CNTs) are attractive matrices but challenged by leaching (physical adsorption) or perturbation (covalent linking). Zeolitic imidazolate frameworks (ZIFs) overcome these issues. However, our recent study [J. Am. Chem. Soc., 2018, 140, 16032–16036] showed reduced cost-efficiency trapped below ZIF surfaces cannot participate in biocatalysis; enzyme–ZIF composites also unstable under acidic conditions. In this work, we demonstrate feasibility using ZIFs to immobilize CNT two model enzymes, T4 lysozyme amylase, both which negligible retained catalytic activity neutral To better understand behavior CNTs CNT–ZIF, characterized orientation site-directed spin-labeling (SDSL)–electron paramagnetic resonance (EPR), is immune complexities caused background signals enzyme–matrix interactions. Our investigations enhanced exposure solvent compared alone; itself directly related substrate accessibility and, therefore, essential for understanding improving efficiency. best knowledge, first time one-pot synthesis employed anchor large-substrate biocatalysis. This report surface upon trapping CNT–ZIF composites. results guiding rational design combinations improve stabilization, loading capacity,