Co-immobilization of multiple enzymes by metal coordinated nucleotide hydrogel nanofibers: improved stability and an enzyme cascade for glucose detection
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Date
2016-03-21
Authors
Liang, Hao
Jiang, Shuhui
Yuan, Qipeng
Li, Guofeng
Wang, Feng
Zhang, Zijie
Liu, Juewen
Journal Title
Journal ISSN
Volume Title
Publisher
Royal Society of Chemistry
Abstract
Preserving enzyme activity and promoting synergistic activity via co-localization of multiple enzymes are key topics in bionanotechnology, materials science, and analytical chemistry. This study reports a facile method for co-immobilizing multiple enzymes in metal coordinated hydrogel nanofibers. Specifically, four types of protein enzymes, including glucose oxidase, Candida rugosa lipase, a-amylase, and horseradish peroxidase, were respectively encapsulated in a gel nanofiber made of Zn2+ and adenosine monophosphate (AMP) with a simple mixing step. Most enzymes achieved quantitative loading and retained full activity. At the same time, the entrapped enzymes were more stable against temperature variation (by 7.5 degrees C), protease attack, extreme pH (by 2-fold), and organic solvents. After storing for 15 days, the entrapped enzyme still retained 70% activity while the free enzyme nearly completely lost its activity. Compared to nanoparticles formed with AMP and lanthanide ions, the nanofiber gels allowed much higher enzyme activity. Finally, a highly sensitive and selective biosensor for glucose was prepared using the gel nanofiber to co-immobilize glucose oxidase and horseradish peroxidase for an enzyme cascade system. A detection limit of 0.3 mu M glucose with excellent selectivity was achieved. This work indicates that metal coordinated materials using nucleotides are highly useful for interfacing with biomolecules.
Description
Keywords
Inorganic Hybrid Nanoflowers, Organic Frameworks, Immobilization, Nanoparticles, Complexes, Encapsulation, Biocatalysis, Nucleobase, Scaffolds, Biosensor